You need to remember that UEFA's worst case, Armageddon scenario is somebody seriously challenging FFP in court, where it will be broken because as everyone involved already knows it breaks about half a dozen EU competition laws.
That's why they pushed us and PSG into pathetic fines (of which 80% was given back) last time. Because they wanted to say they'd caught us and punished us without actually doing enough damage that we fought back.
A 2-3 year ban? PSG aren't going to take that punch. That's the end of FFP. Frankly I don't see them even accepting a scenario where Mbappé leaves, unless they choose that option over selling 6 or 7 players - and I'm not sure why they ever would.