Haaland and Mbappe have many choices and they are very ambitious players so at their ages now, it is impossible to see them playing in Saudi Professional League. Because it will affect their career in national team, performances in big tournaments and if they move to Saudi, they will have to stay there at least two years. They only have zero tax if they spend a whole year which belongs to 2 seasons in Saudi.
Lots of players are going to Saudi league just because of the amount they will be paid, but I don’t think any players will want to go to Saudi league to build their career their, that’s why most of the players that are going to Saudi league are the once that are old already, they just want money because most of them will be hanging their boots soon. Some talented players that went to the league previously just because of the amount they are being offered are no where to be found again, they just destroyed their career because of money. Am sure Mbappe and Haaland knows about this and am sure they won’t want to end their career so early, so am sure the two players won’t even go to Saudi league for now, but I don’t know about later in the future.
if a salary cap is introduced in Europe (which is already being talked about) and players will choose between a salary in Europe and x10 salary in Saudi Arabia, many, maybe even Mbappe with Haaland, will choose Saudi Arabia.
Some players won’t go the a club because of money, some of them will want to build their career and they won’t want to go to league that when they get their, then nobody will be talking about them anymore, Mbappe and Haaland are the two players everyone are talking about currently, if they can go to Saudi league then they already spoil their career already because attention will be shifted from them. Am sure Mbappe and Haaland might end up going to Saudi League when they are getting old already, but I don’t believe it’s going to be now.