Musk wants attention and money to do whatever he wants. Everything else is negotiable.

I don't believe Elon ever stated Twitter has no right/freedom to ban (he does say a lot of bizarre things, and I don't follow too closely), but correct me if I'm wrong. Disagreeing with the Twitter policies is not the same as believing Twitter is not free to establish such policies.

He has stated that he thinks they should only ban if the law requires them to do so. For example he thinks the Trump ban was clearly problematic.

Twitter is free to ban Trump or others, regardless of whether Elon Musk owns Twitter. Whether to implement a ban is a decision their management can take, or not take.