Just when you think a team like PSG has all the advantages to win a match, they will even lose at home to a smaller team. On the contrary, when you will not expect, you will see them delivering beyond imagination.
To be honest, when PSG bought Messi and their attacking trio become Neymar, Mbappe and Messi, I thought that it would be the best unstoppable trio. Even Suarez, Messi and Neymar were doing wonders and when you have Mbappe, who us far superior than Suarez of old Barca seasons, you really expect that such a team will win every trophy but they failed to win Champions League and that was a very sad moment.
It will be very difficult for PSG to release Mbappe next season. He is in top form and a key player that score at any given opportunity. Age is on his side and I feel a sense of nationalism might compel him to remain in France.
Unless perhaps he feels his career will not grow well at PSG base on the fact that they hardly perform well Internationally. He might decide to leave and pursue his career even though it will be difficult to reject the tempting offer PSG will offer should they get to that point.
I also think that Mbappe may reject any transfer because he grew up near Paris, speaks French, born in France, lives in a wonderful city called Paris that is a dream destination for many (but so beautiful is Barcelona). He has salary, great life and everything he wishes, he lives in his hometown. But on another hand, he acknowledges that if he want to succeed and win trophies, he has to move somewhere else and Real Madrid is really the best option for him to win trophies. If PSG becomes stronger, he may stay in the club, otherwise, there is really no reason for such a big talent to be wasted.