If Don Carlo can lead Real Madrid to win La Liga and the Champions League, then it will be a sweet farewell for him and Real Madrid. But I wouldn't have high expectations of what they will achieve this season, because it's not an easy task at all, especially since their competitors have also built their squads during this break.
I haven't heard anything about Nagelsmann and Real Madrid. And also I just heard this rumor for the first time, because previously many speculated about the possibility that Real Madrid would return to their former coach, and that has become their habit.
well, that all we can hope for because Ancelotti was actually a great coach during his time at Real Madrid and now there are rumors of him leaving for another team. I'm a little unsure whether Real Madrid will be able to get their title back in the Champions League next season because next season a lot of teams will change their composition to become stronger and if this is indeed the award from Ancelotti for Real Madrid to win the Champions League title it will be very touching.
Regarding the Nagelsmann news, I haven't heard any news either and it looks like it's just speculation by Real Madrid fans, but my hope is that Real Madrid, at least next season, can get the champions league trophy as a farewell to Ancelotti.
By the way, it is no longer a rumor that Carlo Ancelotti will leave, as he has reached an agreement with the Brazilian National Team to become their coach in 2024, exactly after he finishes the upcoming season with Real Madrid.
Undoubtedly, he is a great coach, he has given many titles to Real Madrid. And it is true that next season is the last season for him to give something valuable to the team nicknamed Los Blancos.
Everyone wants a good ending, and Carlo Ancelotti is no exception. I want to see what he will give to Real Madrid in his last season.

After some time ago being announced as a new Real Madrid player and having started training for pre-season matches, it seems that Arda Guler has not had much luck. He experienced discomfort in one of his legs after training and it is certain that he will not defend Real Madrid later against Manchester United, moreover the club also does not want to take risks if it forces Arda Guler's current situation. If we look at Real Madrid against Milan a few days ago, we also didn't see Arda Guler included in the starting line-up or coming off the bench, so it happened exactly the day before Real Madrid's pre-season game started.
Yes, they should not need to force their players to be able to play, especially since this is a pre-season match and only a match to see how far the depth of their squad will be able to navigate the season that will soon begin.
It's quite unfortunate because maybe they won't see the ability of the player who is forced to rest, but it's better than they have to really lose players because of the injuries they experience in pre-season matches.
Now Real Madrid are dominated by young players, their habits are quite significant in recent years because before they were a team filled with players who were already embedded in them star players, even in 2017 I remember they were a team gathering of captains from each player's country.
At that time they were a terrible team and won three consecutive Champions League titles. Now they are focusing more on young players who will be their assets in the future, a good step, as long as they don't forget that there should not be too much gap, because maybe it will make a mess.