Oh, I am very positive you have to fill out a LOT of forms in order to have a coupe, and call me paranoid, but I suspect it’s very hard to get all the paperwork done in order to mount an actually successful coupe.
I’m betting you’d think you’d fill out the forms then have the uprising, kill the current leaders and then…when it’s all done, discover that the paperwork was wrong, you were missing some approvals, probably the approval of someone you just killed.
So then you’d have to find a priest or necromancer and start resurrecting people to unwind the coupe, refill out the paperwork along with paperwork documented the failure of the first coupe, if you got that done, and you could get the approval of the officials you need to kill, so you could kill them, you could then start over.
However, my bet is that you’d then find some new flaw and have to re-unwind the second coupe, and what is the rule about time between failed coupe attempts? You need to make sure you abide by any legally valid “cooling off periods” etc.
Really, not sure it would be worth the effort.