Well, you signature says it all:
"We'll have people put 400+ hours into a game and then come over to the forums to decry it as "unplayable" without a hint of irony." - icedt729
Maybe even with 400+ hours they have a point. Things like these aren't supposed to happen. In fact, the coup should be canceled if their loyality to you is above 50 or 60, not just for the Zveno but for any faction. And this is far from the only example, the more DLCs the more bugs like these. As someone said once, the developers will only fix a bug if it makes the game literally unplayable. If anything, it's a miracle Hearts of Iron 4 is still such a great game with so many bugs, inconsistencies and things that have no logic. It says a lot about how amazing the gameplay mechanics are, as you don't see many games with equally high numbers of bugs and loyal fans.