~~
I don't think PSG wants Donnarumma to remain in the club because of some reason which includes his high wages. They have already gotten a replacement, Lucas Chevalier. Maybe they want to make money from his transfer fee. I am sure that many clubs will be scared away until the French outfit reduces the fee. His contract will expire next year, and PSG might not get any amount since he would be free to move to any club he wishes.
I don't know what is happening in the world of football nowadays why will a club like PSG be letting Donnarumma leave the team just because of his high wages like is it this season he started taking that amount? He was instrumental for team I their outing in the champions League competition last season and now they no longer want him because they have a replacement for him already who is probably taking less than his salary, they should reduce his transfer fee so that clubs will rush to sign him but keeping him in the team when he is not going to be used will only reduce his chances of getting a better offer from good clubs.
It's said that Luis Enrique also doesn't like Donnarumma playing style, so PSG intention to sell him isn't just about his salary issues. With Donnarumma contract ending next season, PSG will certainly try to push him to leave this summer so they can get profit from transfer fees. I think with Donnarumma quality, he will eventually find a new club, Manchester United and Manchester City are reportedly interested in signing him.