I don't believe this rumor, Kevin still has quite good quality and there are still many top European teams who still want to recruit him.
The top players who want to move to the Saudi Arabian league because of money and also their age are no longer able to compete with young players so before ending their careers they look for more money there.
I've been seeing these reports a lot for the past couple of days and I have purposely refused to pay attention to them because I know they're not true. Currently, Keven De Bruyne is the best midfielder. Some people might ague with this, but it's true. He may not be a midfielder that can control the tempo of the game like Rodri and Gundugan, but he's a midfielder that will give you output. He create so much chancy, he gives assist and he scores goals. Any team in Europe will gladly pay for De Bruyne. That is why I don't believe he'll go to Saudi anytime soon.
The truth is, De Bruyne is not leaving Man City, not while Pep is still the coach. See how Pep made sure Bernardo Silva didn't leave, he'll do more to keep De Bruyne at City. De Bruyne is a kind of player that can get injured, come back and perform like he never left. He is a top player. Pep would never let him go, except he really wants to leave and nothing indicates that he wants to leave.