I think Gasly will be ok. No reason for him to move with Ocon gone and no need to replace him because the car is so horrible no one would make a difference. That, and what kind of blowback would Alpine get if the fired two French drivers?
I think all of us knew this would be a bad pairing. They could have worked together, improved the car together, improved the team together and helped each other to improve results. They could have been the heroes of all of France, but instead the pairing has done nothing but take the team backwards.
Alpine had to get rid of one of them, so they kept the guy who doesn't cause problems with his teammate. Ocon has had trouble with Checo, Alonso and now trouble with Gasly. There was no reason to think that would ever change, so Alpine really didn't have a choice here.