NO

First, the current fallout over pronouns is just the tip of the iceberg. It is the manifestation of far deeper issues. Issues that have been misdiagnosed and treated in the wrong way.

Your proposed solution, while on the surface it might scratch the root cause, still does not solve problems caused by wrong medications and even longer disease.

Poor content, why can't we just leave it there

The fastest way to get helped is being able to help yourself instead of waiting for outside help. Stack Overflow with its immense repository of Q&A is the perfect place where you can go search and find answers to your problems. But it is hard wading through a swamp in search for diamonds. If searching takes way too long, then it is not helpful. If you have to try dozens of answers on poorly asked questions only to figure out they are solutions to different problems then you are wasting your time.

This is why we need moderation and quality control, regardless of what kind of site it is - for newbies or advanced users.

Just as side note, I have been using Stack Overflow for years before I joined. Not because I was afraid or anything else. Simply, I could find all the answers I needed without asking any questions.

Moderation, down voting and close voting and feelings

Any kind of system with moderation based on quality will hurt people's feelings. You cannot moderate in a nice way. This is where the Welcoming policy failed. The problem was not generally in SO being a sexist and racist place, but being a moderated place.

When you receive a downvote, and when your question is closed it will always feel bad. When it feels bad, most of the time people will not try to see how they failed and what they did wrong. They will put the blame on others.

If you by any chance are part of some minority (or some other - fresh developers are most likely not a minority) group, it will often seem that the bad feedback you get is because you are part of that group and that you have been discriminated because of that.

Having said that, in communities this large there will always be incidences of really bad behavior. There is no way to avoid that. But what matters is that the Stack Exchange network has mechanisms that can deal with such things fast. This is what makes some communities at large sexist, racist, or unwelcoming on any other basis or not.

Lack of moderators

The main problem with Stack Overflow is the mass pileup of poor content (mainly questions) and not enough people with powerful enough tools that can cleanup that mess fast. Day, after day.

When all content cannot be moderated fast enough that leaves additional room for feeling unwelcome and specifically targeted. When you can see that some other poor question is doing fine, and yours is not, then it is very hard to accept that you have to try harder. No matter how politely someone tells you.

We are all newbies

While there are certain skills experienced developers will have compared to total beginners, technology changes so fast that we all need to learn new languages, tools, and acquire new skills.

Where can experienced developers go and ask basic question about development stack they never used? Where can they find answers to such questions?

Should they use Advanced SO or Open SO? Would we be able to close questions as duplicates on another site? Diluting knowledge is not a good option.

Blind leading blind

If all advanced users tend to stick to the advanced site, who will teach proper techniques to the newbies? They will maybe receive an answer on the Open SO, but having an answer does not mean you have a good answer. Learning bad coding practices can hurt more in the long run than being hurt over few downvotes.

False expectations

Another prominent issue with Stack Overflow is that new users are not well informed about what is expected of them. They are pushed into asking questions fast without clear up front warnings that asking poor or off topic questions can lead to a question ban. They have no idea what awaits them. They have no idea what the rules are.

Once they hit the ban it is very hard to get out, and this is one of main reasons SO is seemingly and elitist and unwelcoming place.

Wrong premises

It is not true that new users, students and beginners cannot ask good questions. I have seen really nice questions asked by high school students. Anyone can ask a good question if they put in some effort. Maybe not a stellar one, but certainly a question that will not be downvoted and close voted.

Also some questions may seem simple on the surface, but when you dig deeper they can end up being less than simple. Channeling "simple" questions to the Open site may result in not getting a deep knowledgeable answer that can be food for thought even for experts.

Welcoming policy

The Welcoming policy brought very little good. It only made people more nervous. Posting comments seems like walking on eggshells, and you can easily trip over and being flagged for even benign comments.

Comments asking for clarification or an MCVE are not rude/abusive

Under such circumstances, people are reluctant to give helpful comments to questions and tend to downvote and close vote without them. As the end result, instead of making the experience better for new users it is actually getting worse. And experienced users are not feeling good either, to the point they are contributing less.

Policing pronouns will end up the same way. Many misunderstandings, fewer comments, more downvotes, everybody will be on the edge and nobody will be happy.

More independence does not mean fewer rules

More independence for the Advanced site does not automatically imply we can misbehave there. Just like being nice escalated in a wrong way, not having to be as nice can do just the same.

More nice does not mean lower quality

A more tolerant SO does not mean anything will go. Soon enough, the new place will reach the same level of dissatisfaction because it will still require applying some quality standards.

What to do?

• Stop policing people over their language. Taken out of the context, almost anything can look bad. Having respectful, professional conversation is one thing, forcing people to express themselves in particular way is another. We are all living beings, we cannot be put in the box. We all have good days and bad days.

• Give people with moderating privileges better tools to clean up poor content faster, for instance reducing number of CV, as it was done in a recent SO experiment.

• Make it more clear how the site works, what kind of content is acceptable and what are the consequences.

• ...

• And last, but not the least, listen to the community, especially to prominent moderators and contributors. They know what the challenges are, they have valuable insights, and they can offer some answers.