A transfer to Manchester City for Gianluigi Donnarumma seems almost certain, but if you look at the Turkish media, they are still saying he will come to Galatasaray. 
Apparently, Manchester City will pay 50 million Euro for Donnarumma. And then they may sell Ederson. Galatasaray could then acquire Ederson. The likelihood of Donnarumma coming to Türkiye was already very low. Why would he go to a league outside the top five when he could join one of the biggest team in the Premier League? It's still too early for him.
Apparently, Manchester City will pay 50 million Euro for Donnarumma. And then they may sell Ederson. Galatasaray could then acquire Ederson. The likelihood of Donnarumma coming to Türkiye was already very low. Why would he go to a league outside the top five when he could join one of the biggest team in the Premier League? It's still too early for him.I don't think it will be wise for Donnarumma to join Galatasaray when he has an option like Manchester City, because it will be a down grade from my own perspective. He is a world glass goal keeper a day deserves to be playing in the big leagues and I also believe that Manchester City will be a good fit for him.
Ederson is also a very good goal keeper and Galatasaray could make do of that option and it will also be a good bargain for them.