Oh, you did ask a question! I didn't read carefully enough. Thanks for quoting it for me, so that I could better identify what I missed.
Many believe that Trump did not write this tweet because it is not written in his usual tone/voice/cadence/vernacular. It just doesn't sound like something he wrote.
The post title is a joke playing off that and the rumors of his death this weekend, although I believe he had made a public appearance this morning (not 100% sure), so the rumors were not correct.
The "conspiracy" would just be a weekend at bernies type situation where they are covering up the president's health issues or lack of life. It's already been happening consistently with his incontinence, dementia, and hand bruises, so there is precedence. I'm sure Vance would be happy to step forward but he is generally known to be unpopular outside of Peter Thiel's circle within the GOP and does not have the "charisma" that Trump uses to command his MAGA base.
It is just a joke post, originally to a shitpost community, and now crossposted to a political meme community. The original post got a significant number of upvotes, this crosspost is gaining, and you're already being voted down, so it seems that you're kinda alone with this reaction. Everyone else appears to have understood it without issues.
Any more questions?