You say that, but as we all know, UEFA, the FA and the Premier League seem to have very few problems with clubs racking up massive debts. It's owners that invest in their clubs that they have a problem with.
Unless there's a big long-term loss in income, I think a lot of clubs will just register this season as one for the bank loans to pay off. That might mean they have to tighten their belts a bit more in the coming years to help pay off that debt, but I don't think it will financially cripple loads of teams at the top end. Particularly if they're not actually going to get any money for their players. It would probably make more sense for a team like Leicester to keep Youri Tielemans in the hope of qualifying for the Champions League and accept higher debts, rather than selling him in a cut price deal that won't come close to compensating for the lost money anyway. But it certainly might limit teams ability to invest in the squad going forward, which might lower prices for the teams that can afford it. And a lot of that would be determined by what UEFA do about FFP. It would seem ridiculous to keep it in place in a season where literally everyone is going to fail it by millions.