No, there's no evidence.
But it seems trivially obvious that, if Musk owned Twitter, that account and ones like it that target Musk will disappear.
As much as I like Tesla and respect SpaceX, I do note that Musk rarely misses an opportunity to benefit himself.
The whole crypto market manipulation event is one obvious example; what abstract ethical behavior was driving that debacle? I say there was none and that it was a transparent attempt to make money while trolling the crypto community.
Not that I actually fault him for doing that. It just points out how broken the entire cryptoverse is. But my point is that he is prone to doing things for his own benefit and/or without regard for the consequences.
What I haven't seen is evidence that he would take some kind of high moral position on free speech absolutism against his own self interest. To me it's more a question of "prove that he won't do it" than to prove he will.
If he ends up buying Twitter, we'll find out either way.