PSG will be fine with or without Kylian Mbappe, the management of PSG itself already know this more than you do and I guess they have plans on ground to take care of Mbappe's departure from the club, and besides they're going to make some money from the deal and which I they have some players on mind they will be going for after that deal is completed, They only need to get two or three quality players to step the team Mbappe departure from the club and with time the get stronger.
Inevitably, of course, PSG must move forward after losing Mbappe at this time, from the beginning, Mbappe had a very big role in helping PSG win every game they played and so far we know that Mbappe is a mainstay player who is indeed able to make every difference in the final result of PSG matches, admit it or not, of course PSG will be weak without Mbappe and we can see in some of PSG previous matches which actually gets negative results when Mbappe is absent, indeed football is a team sport but it has been clear that if PSG is too dependent on Mbappe, PSG will certainly remain strong if indeed next season they can get new players who are indeed able to replace Mbappe role so far.
Mbappe this season has officially left PSG, although it has been reported that Madrid has been the leading team to get Mbappe, but still we don't know for sure where Mbappe is going next season, I don't know what agreement you mean, if indeed what you mean is Mbappe deal with another club, of course it will most likely happen soon but with the agreement of course PSG will not get money because indeed Mbappe left This season on a free transfer.