"The Russians have a lot of form here," he says. "Throughout Soviet and post-Soviet history there have been suspicious air crashes when rivals were a threat or became too popular. For example, Yuri Gagarin in 1968 and General Alexander Lebed (a one-time possible contender for the presidency) in 2002 both died in mysterious circumstances in air incidents."
Prighozin, sure; he'd expressed all kinds of disapproval of government policy and had just attempted to send his forces against Moscow, had disregarded Putin's order to stop, had been investigated, various patrons and supporters have disappeared in the past two months, his organization was disbanded, many predictions were made from reputable people that he would be killed, and he was flying in a (relatively safe) passenger plane with other top Wagner associates between Moscow and St. Petersburg.
It looks like Gagarin died when doing MiG training under non-ideal conditions, and Lebed's helicopter crashed into power lines. I don't think that those are remotely near being in the same bin.