One scenario -- Prizoghan was not actually on the plane, and this is a false-flag for him to disappear for a while.
a) Putin knows
b) Putin doesn't know
Scenario two -- Prizoghan was on the plane
a) It was an accident by low-level people
b) it was authorized by Putin or close cronies
No matter which of those it was, watch carefully what happens with Wagner forces in Africa, Syria, and Belarus. They are not likely to be happy about what happened. Unhappy, armed criminals are not a good thing.