TMZ only said he was in a coma, and that he was being prepared to receive his last rites which means he is either brain dead and he's being kept alive artificially, or that the coma is going to kill him somehow.
Something is really fishy with all of these conflicting reports. I'm tempted to believe TMZ on this one, unfortunately... As much as I dislike Wayne's music, I hope he's okay.
What would posting a fake tweet do for anyone if they're trying to calm everyone down that's fine. I don't think they'd want to hide his death to the public.