I do not believe that Mbappe will create unrest within the team because he is living his dream. He had a dream to play for Real Madrid and now I can say he is home. Carlo Ancelotti, who manages Real Madrid, also manages Mbappe. I trust Ancelotti in that regard. Ancelotti is a great coach. Mbappe, on the other hand, will also be in Spain with the games he left off from where he did wonders in the French league.
Being at Real Madrid has been his dream since he was little, he was even willing to get a salary below standard just because he wanted to make his dream come true, so it's hard to imagine him causing unrest when he was at Real Madrid. I don't think he would do anything stupid that would harm himself.
Real Madrid is a big club that doesn't just have one star player so Mbappe can't be selfish like when he was at PSG where the club only relied on Mbappe for its success while Real Madrid relied on all the players to create success so if he was selfish Real Madrid wouldn't hesitate to kick him out club.
Carlo Ancelotti is an experienced coach so he will definitely give direction to his players and he will also be a fair coach for his players so that there are no differences. Maybe Mbappe will be treated the same as other players at Real Madrid, there are no privileges or golden children like in this PSG will make other players feel jealous and other players will not play optimally because they feel they are different, so they have to act like players who come to the club and adapt well with their club colleagues.