Mbappe is no small name when it comes to the football world and I believe he has been handling pressure for some time now and him wearing this iconic number will instead boost his confidence the more since he knows fully well the caliber of players that have actually wore and befitted that number of the jersey. His first season alone at Real Madrid shows that he is a player that open to grow and improve in everyway possible.
This is nothing but pure marketing, I respect him for having all of that to his catalog but he should do well to win Laliga and Champions League next season. He left PSG to Real Madrid because he think that the best for him but reverse karma happen to him fastly, same club he dislike won Champions League before him and to say that many people used to think he has pride and all of that, now he is humble and doesn't give attention to media like before.
They should rather worry about what Barcelona is building this season. Real Madrid has been through a lot of tough hand last season and now Barcelona has added Rashford to the same squad Real Madrid couldn't win a single El clasico, it's better they have another solid way of encountering Barcelona at any game else all this shirt things they afr marketing wouldn't change anything, he is only going to be losing his values more and more as seasons goes by.