I know that UEFA cannot sanction any club in the Arab because it's not in their jurisdiction. But I believe the level of conspiracy in football. If they cannot directly control, they can indirectly influence. If they cannot indirectly influence, they can also regulate the clubs in Europe on how to sell to Arab.
The contract that offered by saudi clubs were not so long unlike european club. Remember that the player like kante was got only 2 years contract. Ronaldo's contract was not so long too.
EUFA can strengthen its rules to make sure if european club will not able to sell players to the arabian clubs but the problem is, there are so many investors that came from saudi. Will UEFA prevent them all to put money into the european clubs?
I dont' think so.
It is correct as you said that this wave of buying expensive players will not sail for long. If you keep investing without an equivalent return of investment, that type of investment is not always sustainable. They Arab club owners will soon get tired, maybe their next move will be to buy clubs in Europe.
Only time will tell us. Arabian club will always be relying to the oil money. As long as these will not be stopped and it can help the league to sustain with so many stars on it.