He certainly won't lose his club, but the problem is how to get playing time back, as Luis Enrique hasn't included him in his plans for this season. His contract expires next season, so staying at PSG offers no guarantees, which could actually create a bit of a problem for the goalkeeper. I'd prefer him to move on and find a club that wants him, and we can see two English clubs interested in taking him. His condition isn't great, but I'm sure he understands the problems he's facing, and PSG will certainly let him find a new club.
If Donnarumma and PSG don't capitalize on the current transfer window, both will suffer losses. Gigio will likely be benched, potentially for almost a season. For PSG, this represents a financial loss, given that Gigio only has one season left on his contract, meaning they likely won't receive anything in the future. One option is to lower the price; I'm sure Manchester City will try to meet this requirement so they don't have to wait to sell Ederson.