Those tweets are damning in the sense where he went from clear DPOY to traffic cone, but as far as the offense goes... Wemby has been settling for jumpers all year long. He almost never catches the ball on the post, and even when he tries to setup in the high block or elbow asking for the ball, he always gets bullied out to the 3 point line by guys a foot smaller than him. He just doesn't have the strength, know-how, or both to be a force down low right now, and his jumpers falling have conditioned him to think that's his best option.
That's not a recent thing, that's been like that for most of the season
Edit: to add to that, he's one of the worst screeners I've ever seen for a high level guy, so the PNR doesn't help him with any of this stuff either