Modric is getting too old, so it's understandable that he's leaving, and it won't change anything. In fact, it's a good thing for Real Madrid to regenerate the team, especially in their midfield.
A new era for Real Madrid is slowly being built, and I'm quite optimistic about it. Real Madrid has been developing many young players for the past few seasons, so it won't be difficult for some of the senior players to leave.
Xabi Alonso is also a coach who is quite adept at combining young and senior players. This was evident when he was the manager of Leverkusen last season, so what he will do with Real Madrid is likely to be the same.
It will take time before the team starts to grind out as Xabi Alonso wants, regarding Modric there was nothing else to do but give him away I know that for the Real Madrid fans it is very painful but it is something that had to be done and as soon as possible, on the other hand he will play for Milan and therefore he will be able to continue his career