I find it rather subtle :
* In recent history, another great would-be putchist, Lin Biao, died in a plane crash after the failure of his coup against Mao Zedong,
* The accident has killed two birds in one stroke : the "political" and the military boss of Wagner.
* In Greek Mythology, a fatal fall is the standard punishment for those who challenge the gods' preeminence : Bellerophon was unhorsed for attempting to fly up to mount Olympus, and Daedalus' son, Icarus, fell down into the Egean because he wanted to fly too high. Actually, this is not strictly a Greek thing : the myth of Lucifer and his "fallen angels" is another illustration of this theme. The Gods punish those who challenge their order, making them fall down.
The message is all the more striking : it's not Putin who punished Prigozhyn, it's God. Please remember that Putin tries to appear as the defender of the orthodox Church, the new Tsar ... Besides, it is often pointed out that the far-right supported Prigozhyn. Isn't the Russian Far Right ultra-orthodox ? Letting "God" assume the responsibility of punishing the rebel is an astute way to show that he had made the wrong choice, and that Putin was the rightful ruler.