Even that is possible, I don't think Kylian Mbappe will be playing in the Arab Pro League at the peak of his career as he is now. Instead of playing in the Arab Pro League, I would expect him to play in the Premier League or La Liga for the next few seasons and win his first Champions League title. Kylian Mbappe is also eager to win individual trophies like the Ballon d'Or and others, so the chances of going to the Arab Pro League are currently very low.
I believe its best for Mbappe to move to Real Madrid; he had an amazing performance in the worldcup and also finished the season on a high with excellent performances but he is no where near balon d'or shouts after being overshadowed by Haaland treble win and Messi world cup win. A move to Arab means he is planning retirement soon haha