I think his ceiling is clearly above that. A problem is due to his shot blocking being what he's known for, the comparisons of him are to shot blockers, more pure defensive guys. Chandler outside of dumpoffs and screen/rolls, you ignore on offense.
Big Willie has a completely different feel for the game. Has some pretty good passing instinct about him. Is quicker and looks like a guy who can score off 2-3 dribbles around the paint. He has a touch inside that none of the Chandler/Ibaka/Jordan types have. Much more fluid.
I don't want to get ahead of myself but he's much more an Anthony Davis type to me, without the midrange jumper. And I say that because Davis is more the ultimate role player type than a go to guy, at least until he adds to his game.
Of course when I see this, the form he has, combined with the touch we've seen from him, an NBA jumper seems like it'll come with a matter of time.
His movement is very similar to Davis. Ultimately, if he becomes an All NBA level defender which he clearly has the potential to do but also become more a poor man's offensive version of Davis, we're looking at an All Star level and potential HOF level player on our hands.
Not to get ahead of myself lol. But talent is talent and his talent is rare.