Just a quick analysis on Palace (based on accounts to 2024).
1. They are not at risk under Premier League PSR. They have been consistently loss-making, but not huge amounts (£25-35m per annum before allowable adjustments), and they were probably at something like £50m v the £105m allowable loss last year.
2. Their figures are pretty consistent in recent years, and the difference between slight drop-off in PL media (lower finishing position) v FA Cup win will probably be negligible, possibly even positive if they exploited the FA Cup run well enough.
3. They haven't been dependent on player trading in recent years, but will have made a decent profit on Olise in the current year (compared to a total of less than £2m profit on player sales in the previous 3 years).
4. However, they may struggle to meet the UEFA squad cost control measure next year. I reckon they're at about 80%, UEFA's target is 70%. That will be helped by Europa league income, sales of Olise (and possibly Guehi), but they'll need to get a handle on wages and be careful how much they re-invest. NB - they don't need to complete sales before the end of the month, UEFA's rules work on a calendar year so they can count any sales this window. They have enough wiggle room on Premier League rules that they don't need to do a deal this month for those rules either.
So I don't think they're in a pickle. If they fail UEFA's squad cost rule then they'll get a fine, nothing more, and probably just a few £m. They may even get away with it given their participation in Europe is probably a one-off and their past results suggests they don't take the piss.
But I think they're pragmatic enough to know they're better off selling Guehi and bringing someone new in, rather than keeping him and letting him leave on a free next year. I also think they know that when they recruit players they need to keep a reputation as a club that won't stand in the players' way if they want to leave for decent money.