Putin had him killed. Prigozhin probably thought he was safe for some reason, but Putin took the first good chance he got to take him out. To me that’s the likeliest option. It is theoretically possible the whole thing was a stunt of some sort, but I don’t believe it.

I am really surprised, almost flabbergasted, that apparently nobody has made an AI fake video of him claiming that he’s still alive.

Probably exactly what has been reported. Putin waited for things to settle, weakened Wagner troops by taking their weapons and splitting their numbers, then they killed leadership. Occam’s razor certainly points to this.

But, of course, the way it was done certainly leaves the door open for conspiracies.