While Control was an excellent novel - easily the most enjoyable Section 31 tale from me since Abyss - I think that the fallout from it could be even more interesting. The people Sci named that were involved in the Zife coverup were (as far as we know) not directly part of Section 31, but that doesn't change the fact that what they did was remove a elected head-of-state from office in a highly illegal manner. I suspect Picard might survive this as he didn't really take part in the coup (but still allowed it to happen). People like Nechayev (one of my favorite characters) however, with her background in intelligence and all, are likely now in serious trouble.
Frankly, I would anticipate, at the minimum, Nechayev, Nakamura, and Picard all being arrested by Starfleet Security and court-martialed, and Jellico, Ross, and Lagan being arrested by the Federation Security Agency and indicted by a Federation grand jury. (I think? I'm not sure what happens to former members of the Armed Forces who have received a discharge when major crimes they committed while in uniform come to light -- are they subject to the military courts system, or are they subject to the civilian court system?)
Nechayev, Nakamura, Picard, Jellico, and Lagan would probably be quickly found to have been unaware of Zife's assassination, since Ross had assured all of them that Zife and co. would be getting false identities. Ross would probably end up taking the majority of the public scorn -- at least, unless the released Section 31 files indicates that
he was forced to cooperate with L'Haan at gunpoint, too.
I find myself wondering if the whole thing will tarnish public memory of Bacco, since she was retroactively complicit in the cover-up of Ross's coup and Zife's assassination. On the other hand, I can picture Ross keeping that information to himself, out of loyalty to Bacco and to the public's need to have had a president they could believe in.
In the wake of the events of The Fall, this might prove one crisis too many for many of the Federation's citizens and allies. I suspect Martok at the very least would need to have part of his office redecorated after getting the news,
I find myself wondering who Martok might want to vent his rage on if he were to request extradition. I suppose the obvious targets would be L'Haan and Ross, since they were, IIRC, the "leaders" of the two sides that forced Zife out.
though I suspect Kamemor and Garak, as a products of their respective societies, would perhaps be more understanding but will likely come under fire from their own opposition if they continue to support the Federation.
I'm not convinced the Romulans or Cardassians would care particularly much about the revelations of what happened to Zife. They would probably almost certainly make noise about wanting Section 31 operatives active on their worlds to be extradited to them, however. But yeah, on balance, I don't see the revelation of Section 31 as fundamentally altering their relationships with the UFP.
And losing faith in leaders they elected in good faith, or their principal support staff, might have lasting consequences for the Federation´s citizenry, regardless of Control´s final thoughts on the matter.
I mean, Ross is the only person who knows that Bacco knew about Zife and kept quiet on it -- it's questionable whether or not Uraei would have bothered to include that in any Section 31 files. Meanwhile, of course, zh'Tarash is an idealistic political outsider who almost single-handedly led her world back into the Federation and who then immediately acted to purge the government of Section 31's influence. And Bacco seems to be almost universally beloved, and had no ties to Section 31. So while I think Federates will certainly have their faith in Federation democracy shaken, and while I think they're going to have to come to terms with some pretty major problems with Federation political culture that have allowed three different coups or coup attempts in the past decade and a half, I also think their selection of zh'Tarash the previous year means the UFP and its citizenry are in the best possible position to deal with these revelations.