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.
Of course, the Saudi Arabian league is very different from the top European leagues, so players who feel they are still worthy and still have quality will not feel at home there.
But it is quite correct, that many elite European teams are also very interested in recruiting Kevin De Bruyne because he is a fairly quality midfielder. From the rumors circulating, it is true that the team from the Saudi Arabian league wants to bring Kevin de Bruyne to their team, but of course the decision is all in Kevin hands. But we know that Manchester City always does business well in every decision they make, meaning they have a big opportunity to make big profits from selling Kevin. Moreover, currently Manchester City has not offered a new contract for Kevin, so of course Manchester City will sell Kevin in the summer transfer window.
The price tag circulating is that Manchester City has set it at £100 million and it is likely that many big teams with strong finances will make their offers for Kevin. I'm sure Manchester City will definitely accept a big offer, but still Manchester City and Kevin will both choose what is best for Kevin career. So if he doesn't want to go to the Saudi Arabian league team, I'm sure Manchester City will grant his wish to reject all offers coming from the Saudi Arabian league team. Kevin was an important player in the Manchester City team in the previous few seasons so the joint decision will definitely be a point in the transfer process where it is to appreciate Kevin services who have provided many trophies for Manchester City.