I don't think Pep Guardiola is ready to release Kevin De Bruyne anytime soon, especially considering that the player's contract will be ending in 2025. We can be quite certain that he will remain in Manchester City until then. Pep Guardiola has mentioned in his recent comments, as reported by Goal.com, that he would not influence the player's decision to leave. Guardiola stated that he would not interfere with Kevin De Bruyne's departure unless the player himself decides to leave. It seems that De Bruyne may wish to stay in the club and retire at the Etihad Stadium, but, the decision lies with the player. It's also worth noting the interest shown by MLS and SPL in the talented player as they have indicated their interests for him after he leaves the Premier League.
I agree with you there is no reason for Pep to release this player, we know that Kevin de Bruyne is one of the most important players in the Manchester City squad. I still remember when this player was injured, Manchester City's performance dropped dramatically so obviously Pep doesn't want this to happen, unless he gets a new player to replace that position.
Indeed, based on age, Kevin de Bruyne is an old player with 32 years old this means that is the ideal time to join Saudi Pro League but he still has other considerations before deciding to move to this league. Please note, if Manchester City won 2 important titles this season Premier League and Champions League then there is a possibility that Kevin de Bruyne will move to this league because he has got all the titles so he has a reason to find new challenges in other leagues.
It true, De Bruyne is one of the main players in the Manchester City squad and De Bruyne presence has had big influence on Manchester City success in winning every match they have played.
Even though Manchester City could get large amount of money, let alone sell De Bruyne to Saudi team, I not sure Pep would do it, unless it was decision taken directly by De Bruyne.
It just that it looks like De Bruyne will never leave Manchester City until his contract actually expires, he can earn big salary when playing in the SPL but he is of course much more concerned with titles in his final retirement years than chasing money.
Moreover, if De Bruyne wanted to leave then he could have done so since the previous transfer window and he could have played with one of the Saudi teams but in reality De Bruyne did not do any of that.
This season, Manchester City has big chance of winning the Premier League and UCL titles, so it can be confirmed that when Manchester City actually gets the title, De Bruyne will be even more confident in staying and spending his contract period fighting for the title next season.