It was the transfer everyone had been waiting for for years. I think no one doubts his performance. He's going to be the new star of Real Madrid. My only question mark about Mbappe is about his ego. If he doesn't have problems with his teammates, he can show great performances and stats for years at Real Madrid. We know that he made great sacrifices to transfer to Real Madrid. He was under pressure from Paris Saint Germain when he did not renew his contract with them. I don't think he will make a problem out of small details like his shirt number.
It's a good thing that Mbappe is been signed by Real Madrid for five contracts but my area of concentration is where would Ancelotti choose to play Mbappe fully as his wing since Ancelotti likes playing 4-4-2 or 4-3-1-2 formation for Real matches. Let's not forget that there are quality players like Rodrigo, Vinicius, and Bellingham occupying such playing formations at the frontline.
I think that by next season, Ancelotti will introduce another tactical formation of 4-3-3, to bring Mbappe in, in every Real Madrid match of Laliga or Champions League, to avoid issues or confusion that will arise based on how to feature Real Madrid frontline players