This the greatest opportunity for PSG to reform their squad since some big names will be leaving the club. They shouldn't make the mistake of buying more super stars, they should just buy good players and Mbappe wil Lord over. This will bring peace and stability in thr team. And if PSG is not able to solve this problem now, they will still go next season unrewarded in the Champions League.
One exceptional leader with other good players.
Yeah Messi has left for Inter Miami already and there are speculations about Neymar to leave this summer as well. For now there is no official for Neymar but if there is it looks like it would be from the English Premier League. So far I have heard of Manchester United and Chelsea's interest in him but let's see how things will go. His cost would be quite a lot for a player at this age and in addition to that he is injury-prone as well.
Let's say he was signed anyway then PSG will need to build a new trio in the attacking line in Mbappe's lead. As they have nothing more than money they can do this successfully I assume. But they had better start with changing their manager first to take the right steps after that.