It might be sayonara already. There’s a good chance Jack can’t film anymore, maybe he can’t walk, maybe he can’t use the other arm, any number of serious symptoms. My bet is that his speech has been severely affected, and not just physical parts like moving mouth and tongue but neurological problems like vocabulary, aphasia, etc.
I think if this wasn’t the case he would have already filmed and released a “checking in with YouTube from the hospital” video - Jack did talk about his strokes in past videos, so I don’t think they would keep the illusion up quite this long.