Well, we know he was the boss in 2015, but that it was a completely arbitrary title and he held no power in the family. Something could have changed in the time between then, but we don't know.

My opinion:
There really isn't any obvious reason why Peter Gotti wouldn't still be boss. It is a completely ceremonial title. He's still in prison. He's still not getting out.
I wouldn't say that anybody particularly WANTS Peter Gotti to be boss, but I'd say that nobody cares enough. He's not changing anything. He's not making decisions.