What begins? You knew that those aircraft were the oldest in the fleet. And that if JB still wants 319s (which they have said they don’t) they would accept the 319NEOs NK has on order, rather than changing them to other 32xNEO variants, which they have announced their intention to do. Why not get rid of your least efficient and most maintenance intensive aircraft if you are having such attrition problems you are unable to fully staff the fleet you have. Especially since JB has no desire to have them in the inventory when they take over.