After reading the answers to this question, I noticed something odd: Ukraine appears to have abstained in the recent vote over China's policy towards the Uyghurs.
However, given the context of the Ukraine war, Ukraine's continued existence as a state is entirely dependent on Western largesse keeping the flow of arms flowing.
Why would they vote against their Western benefactors and risk the flow of weapons being slowed or cut off?
This article on Radio Liberty (Ukr, Eng) contains thoughts of some analysts on this matter (highlight mine):
Yuri Poita suggests that there is still a part of the [leadership] in the Ukrainian government [that still] believes that China’s position in the Russian-Ukrainian war can be changed [in favor of Ukraine]: “this is such a strategy “not to annoy the dragon (China – ed.) at a time when when Ukraine fights with a bear (Russia – ed.)”.
In 2019, China became the largest trade partner of Ukraine, and according to the results of 2021, China accounted for approximately 15% of Ukrainian exports.
[…] Now Ukraine is no longer dependent on China [that much], says the expert. He emphasizes that Kyiv’s efforts to “please” Beijing are unlikely to work.
Also, it's no secret that Chinese government has actively lobbied against this very decision. Here's how Taipei Times puts it:
Following an intense lobbying campaign by Beijing, many of the votes against and abstentions did not come as a huge surprise.
However, the decision by Ukraine, which relies heavily on Western backing as it battles Russia’s invasion, to abstain in the vote caught some off guard.
The decision was also criticized by Ukraine politicians: Mykola Knyazhytskyi, People’s Deputy from “European Solidarity” wrote:
It’s a shame. After the indignation of the allies and Ukrainians’ rejection of the position of our representatives in the UN institutions regarding the voting on the discussion of the genocide of the Uyghurs in China, Ukraine changed its position. Would you like it that way.
Continued quote from Taipei Times:
In an unusual move, Ukrainian Permanent Representative to the UN Office and other International Organizations in Geneva Yevheniia Filipenko yesterday took the floor asking that the “record of the proceedings reflect our position in favor of the adoption of the mentioned decision.”
Council President Federico Villegas said the UN body would “take note of your statement,” but stressed that “in accordance with the rules and practices the result of the vote ... will remain as it was announced yesterday.”
Even if the result had shifted to reflect the changed vote, the resolution on China would still have failed, by one vote.
Beyond the official explanations, some extra context here:
China has abstained on many of the [Western supported] UN resolutions related to Russia's invasion of Ukraine rather than outright oppose them.
The issue of Xinjiang is much more important to China than it is to the West. EU's response to the matter, beyond some UN votes has been much more tepid than USA's. (IIRC the US put some import sanctions on the province, while the EU just added a few provincial officials to a list.) So, I think China was much more likely to take some kind of retaliatory measure (officially declared or not) against Ukraine if it were to poke China on this [voting for] than any of the Western countries are likely to punish Ukraine for abstaining.
If China wanted to hurt Ukraine in return, China could definitely do a lot that it hasn't done in terms of helping Russia more during the war, even semi-covertly. Chinese combat drones could start showing up (as they did e.g. in Libya or Ethiopia) and China could claim some other country sent these from their own stocks etc. To say nothing of economic help for Russia.
The Chinese press and even party officialdom has been definitely more anti-Western than their UN votes suggest, blaming NATO for the conflict etc. There is probably an anti-Western faction in China that wants to see/use this as China's proxy war against the West. But they insofar don't have the upper hand in Chinese internal debates, at the levels that matter. Feeding the ultra-nationalist "wolf warriors" with extra reasons to hate Ukraine could tip that balance in the internal Chinese politics. (The Xi government is not totally immune to the popular opinion, see e.g. how they abruptly changed tack on "zero Covid" measures this winter; according the the Western press that internal debate in the CCP also had its factions.)
Someone suggested in comments that Ukraine wants to see the Donbas affair as an internal matter just like China wants to see Xinjiang that way, so that's why they abstained. This may have been a much more plausible reason before the overt Russian invasion, but in the current circumstances it's probably not even in the back seat [of their mind], more like in the trunk. This kind of reason makes more sense with respect to India's abstention vote on the same matter, although the exact nature of the minority perhaps played a role there too. (FTWT, they did give an official explanation that "the Ministry of External Affairs (MEA) said the vote is in line with Indian policy of not voting on country-specific resolutions". Some have quickly pointed out that India did in fact make exceptions to that.)
Aside: Ukraine is hardly the only European country to hesitate on the matter of Xinjiang. Although not at the UN, the Swiss position/response has been even less than that of the EU.
Ukraine is trying to improve relations with China as you can see with what Zelensky is doing, he appealed to China many times, why worsen relations with your potential benefactor and if Ukraine DID vote against China, China may as well aid Russia.
Unless they really say so this seems like a question that's hard to answer. However, as a guess/opinion, look to recent events:
Ukraine war: Zelensky wants Xi Jinping meeting following China's peace plan. Remember, the West pooh poohed said peace plan.
The peace plan is rather bland and unspecific. The West sees it as not condemning Russia but really, what it's in it can sway China either way:
Respecting the sovereignty of all countries. Universally recognized international law, including the purposes and principles of the United Nations Charter, must be strictly observed. The sovereignty, independence and territorial integrity of all countries must be effectively upheld.
Ceasing hostilities. Conflict and war benefit no one.
The safety of civilians must be effectively protected, and humanitarian corridors should be set up for the evacuation of civilians
China opposes unilateral sanctions unauthorized by the UN Security Council. Relevant countries should stop abusing unilateral sanctions and "long-arm jurisdiction" against other countries,
China has its own motivations, as other answers have said. But above all, China has always demanded respect.
If Zelensky puts on a good show of appealing to Chinese benevolence and stresses concerns that are part of the Chinese official line, China probably won't turn against Russia and will remain on the sideline. Public opinion may warm towards Ukraine - Russia's actions are after all fairly hard to really justify, Ukraine easily gets the sympathy benefit with many. If they put egg on China's face, there is a possibility that either Xi himself, or due to not wanting to appear weak to his nationalists ("strong China" is the CCP's selling point) they will start to support Russia more. As the US has claimed they might.
Getting on China's good side may yield UA some benefits (they have a UN veto as well though there are 4 more anyway), though it probably won't until China has realpolitik reasons to ditch RU. Being seen to publicly disrespect it could go really badly for UA.
Trying to win China aboard, as Ukraine is doing with the peace plan and not casting an anti-China vote on the Uyghurs is really quite clever. It would be stupid of the West to risk the overall trend in the UA-RU war by insisting that UA condemn China thus pushing it to support Russia: Chinese weapon deliveries would move the needle a lot more than Belarus and NK junk. I don't know if anyone is tracking what the Western promoters of the pro-Uyghur/anti-CCP vote are saying about abstainers (if they are saying anything). But I wouldn't be surprised they'd keep a low profile on criticizing Ukraine.
Since the war started China has a no-limit friendship with Russia that has limited itself to buying Russian oil. The West wants to keep it that way.
This is a game where everyone knows that the other knows that they know.
