PSG absolutely did.If any club has broken the spirit of FFP over the years it is FFP. Taking Neymar from Barcelona and then Mbappe from under the nose of Real madrid was in the face of UEFA. I don't have a problem with it because I don't like the device anyway but PSG beat a bent system. Don't tell me PSG upheld the values of FFP.
Just recently you have Juve offering a 2 year loan deal for Morata + option to buy. Loan with obligatory (or not) option are nothing new in football. The only thing that has annoyed people in the case of Mbappé is the high value of that option.
It was up to Monaco to decide if they wanted to accept that offer and they did. I see nothing wrong.
FFP doesn't tell you you can't propose a loan. FFP does tell you you need to balance your account to break even. UEFA decided take into account the amortization of Mbappé since the loan year as if it was a direct transfer ( the loan was actually optional with the trigger being PSG not being relegated and UEFA decided it was an obligatory option due to the nature of the triggering clause).
So, again, not a scam. PSG highly respect FFP as they can't even complete the loan of Dele Alli. We all know they could buy anyone if they weren't respecting FFP scam.