The competition to become Real Madrid's main goalkeeper in my opinion is not the most interesting thing to discuss repeatedly, of course, because in my opinion we already know the difference in the qualities of the two goalkeepers.
Ancelotti borrowed Kepa from Chelsea to become the main goalkeeper due to Courtois' injury. Meanwhile, Lunin, who incidentally is Real Madrid's second goalkeeper, will still be Ancelotti's second choice, unless Kepa has performed poorly in a number of matches. Kepa Arrizabalaga is one of the good goalkeepers so far in Europe, but I don't think Lunin has been on the same level as Kepa.
I don't understand why you say that the goalkeeper's position is not the most interesting thing to review. Aren't they the tip of the defense that takes priority in maintaining the balance of the team in every match that is played. I think it's difficult to find a replacement commensurate with courtois for his level of skill at keeping goals from conceding.
Lunin is very close to the Real Madrid players and the players want Lunin to be a mainstay for Real Madrid before Courtois returns to the field. However, Kepa recruitment also reaped great praise because he is a slick goalkeeper at European level but last season he did not perform very well with Chelsea.