Hamas ARE the Palestinian leaders. They won a parliamentary majority in Gaza's last election. The only other Palestinian leaders besides Hamas are Fatah, the former PLO. Fatah is the de facto Palestinian leadership of the West Bank.
Note that Fatah leaders (Palestinian leaders who were not Hamas) who criticized Hamas in the past were executed, e.g. thrown off of multi-story building rooftops, in 2007. Hamas Calling Card via New York Times, 2007:
Killing its political rivals execution style in the streets, in
hospital shootouts, and by throwing them off the rooftops of high-rise
buildings. Since then, arbitrary detention, torture and enforced
disappearances has been a hallmark of the regime.
These sort of public, extra-judicial killings in 2014 make it unlikely for anyone, be they leaders or civilians, to voice dissent with Hamas now:
Hamas carried out the summary execution of at least 23 Palestinians
and the arrest and torture of dozens of others, including members and
supporters of Hamas’s political rivals, Fatah.
More recently, in July 2023, the Associated Press reported:
Hamas rules Gaza with an iron fist, barring most demonstrations and
quickly stamping out public displays of dissent.
Given this precedent, in the recent and more distant past, it is unlikely that any Palestinian politicians or leaders who were part of Hamas or the Palestinian Authority would be likely to criticize Hamas publicly, on the record. In fact, Palestinian Authority (West Bank) President Abbas condemned violence against civilians, including Israelis, initially. On 12 October 2023, Reuters reported :
"We reject the practices of killing civilians or abusing them on both
sides because they contravene morals, religion and international law,"
the official Palestinian news agency Wafa quoted Abbas as saying.
Several hours later, Abbas's critique of Hamas was removed from the Wafa Palestinian new agency article, also reported by Reuters. On the 26th of November, Jibril Rajoub, secretary general of Fatah’s Central Committee, justified the October 7 massacre by Hamas as "an act in the context of the defensive war our people are waging".
The answer is no, none have publicly condemned the 7 October 2023 atrocities as immoral.