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.
If Guardiola was asked about this question in an interview and he said he has no information about such news but he thinks it's possible but will love him to stay, then you can say that Kevin is such a valuable guy that every team would want to be included in their game. It doesn't make sense for Saudi to demand for him but they have the money isn't and football these days is all about what the player earned, people don't really care so much about the talent which is the reason we are were we are today, no too much skills players again.
It's left for him to decide, he is not too young and not too old, he is already almost at the peak of his career but the fact that he is no 3 in the last concluded Balon D'or could work out these time between him and Haaland most especially if they win the Champions League and the Premier League, it's nothing new to them, it's what they can achieve with the current squad of Manchester City.