Assuming the good guys are in full control - these people are having their identities put an end to. Perhaps those identities were part of this operation in the first place. Deep cover operatives could have held "fake" IDs for decades and those have now reached their end.
The deaths look somewhat suspicious - but they also accomplish something practical - these people would be harassed to no end during the coming proceedings. This completely gets rid of that and allows the people who were playing those roles to return to a normal life.
That is an optimistic way of looking at it.
The more cold and utilitarian way of looking at it is that recorded evidence is stronger than witness testimony. If the deep state is trying to tie up loose ends, it is already too late to do so, and so the deaths, while regrettable, are acceptable in terms of losses.
It doesn't make sense that they would be able to time so accurately, however, if the enemy gets a vote. Not unless they are so predictable that their rise to power was scripted in the first place (a concept I haven't excluded from my own theories, but the world could also all just be a simulation - so choose where to spend your philosophy points). This leads me to believe it is now time to retire the identities of a number of undercover operators at the center of this whole mess. Many others could simply "go dark" and slip off the books in a move like a reverse witness protection type of thing - but the ones playing roles like Seth Rich will need to be retired if they want to be able to still live - and the easiest way to do that is to kill them off so that any pursuers of vengeance would have extreme difficulty locating and ruling our doppelganger effect.