For the context of anyone reading this comment, this is the relevant snippet of video people are referencing as their evidence for this video being AI. It's a couple of links deep from OP's link, and I think having it here helps.
Also he linked his own comment explaining why this isn't AI, which while not intrinsically dishonest, is important to note. This isn't someone who read the comment and was convinced spreading it further, it is just a person signal boosting their take.
You are free to update the comment with whatever context you think is necessary, I included the snippet of video most of the discussion was about; I apologize for not including a snippet that included the change in the trees in the back of the shot as well. The included clip does have a weird morph on the sleeve in the left half of the screen that is also implies either an edit or artificial video.
I think the reason people are so quick to believe this is a generated video is because the current administration has already openly and willingly been spreading AI generated content including Trump. This doesn't feel like a stretch, particularly in the wake of his highly publicized absence from the public eye.