Real Madrid confirmed that one of its players who had just returned from a loan period from Milan was Brahim Diaz. We know that his actions have been great for several seasons and with Milan he also led the team to win the Scudetto in season 21/22. Now Real Madrid's attack line has more and more player options and I think this will be the start of Real Madrid's rise in all competitions next season. Brahim Diaz's contract expires at the end of the season, but he has also reached an agreement with Real Madrid to extend his contract until 2027.
Brahim Diaz has proven that he is a good player, he won the Scudetto with AC Milan and he contributed very well. After his loan contract expires in AC Milan, he deserves to be a part of Real Madrid squad for the next season. Since Asensio has left the club and maybe there are midfielders to follow the same way, Real Madrid needs a player like Brahim Diaz that can play in some position in the midfield line and as the winger as well. It is a good decision if Real Madrid already offered him a 4 years contract (until 2027).Im not sure if madrid, barcelona and atletico will able to always dominating the league. 
Sure, no guarantee that these teams will always stay in the top 3 of La Liga. But since they are the biggest teams in La Liga, which means they have more ability to maintain and improve their squads. So, they have a big chance to dominate La Liga with their quality squads.