It seems unlikely Surovikin knew anything about Prigozhin’s revolt: Surovikin’s support of the coup would shift the public’s expectations of its success, which would in turn help the coup succed. Coups are about credibility and collective expectations: The more likely a coup seems to be to succeed, the more people who will support it, the more likely it is to actually succeed. This is part of the game theory of coups. It is why coups often focus on seizing television stations, radio stations, etc. The point is to make the coup seem like a done deal. In short, coups are about psychological momentum, and Surovikin's name would have added a great deal.
Let’s assume, for the sake of argument, that Surovikin was aware of the coup and decided to support it quietly, waiting to see how things would shake out. He would have to anticipate the eventual discovery of his involvement. After all, in for a penny, in for a pound. People will bring up Rommel as a counter-example, but Surovikin knows how Rommel ended up. You either speak up and oppose a coup immediately or you join in wholeheartedly: You do not wait and see. That is a good way to end up dead.
Surovikin did release a video urging Wagner soldiers to turn back: And in doing so, he may have put a target on his head. First, this makes him look more proactive than Putin himself—which is bad for Putin. It also causes him to stand out from among Putin’s other generals: Which might make Putin suspect something. That said, of course, this is the opposite of what you would want to do if you had provided support to a coup: Of course, Surovikin may have acted out of fear.
Possible explanations, with associated estimated probabilities:
Putin is simply scapegoating Surovikin, likely because he is unhappy about the withdrawal from Kherson and his failure to regain the initiative in Ukraine: 30%
Shigou and/or Gerasimov have cleverly found a way to implicate him and they are using this opportunity to eliminate a rival: 10%
Some other party within Russia, perhaps the FSB, is implicating him in order to eliminate a man they find annoying and give Putin a scapegoat: 10%
He was actually involved in the coup but, not understanding how coups work, decided to support it quietly: 20%
He was interested in supporting an action against Gerasimov or some other part of the Russian MOD, but he became frightened once it turned into a coup against Putin. 20%
The Ukraine or the CIA found a way to frame him in order to sow discord into the Russian military. 3% to Ukraine, 2% to the US
Something else we have not considered: 5%
If Surovikin did participate in the planning of the coup without actually moving to actively aid it, then he is incredibly ignorant of how coups work. I find it much more likely that Putin is looking to make an example out of Suovikin. If this is, indeed, what is happening, then we can expect Putin to eventually renege on his deal with Prighozin by having him assassinated.