Is the transfer summer officially opened?
Or do you mean that they are not making moves for the players they need to sign before the beginning of next season.
PSG team is not that bad, they can go another season like this without signing any player despite losing Mbappe as he has already agreed a deal with Real Madrid.
It is not too late for the PSG management to sign players, in fact, they can do as many signings as possible after this current Euro competition.
Several transfer windows have actually opened at the moment, like as the English league which did indeed have a summer transfers opened on June 14 and coincided with the first Euro match of the year, but for Ligue 1 they will officially start the transfer market on July 1 later, this summer transfer market is of course an opportunity for teams to recruit players according to their needs for next season, In addition, of course summer is a crucial time for a club to prevent their best players from leaving for other clubs, at the moment we do not see any active movement from PSG to sign a player who can indeed replace Mbappe role next season, but I think maybe they are currently moving behind the scenes to get the player and make it official when the transfer market opens.
To face the competition in ligue 1, of course, PSG does not need additional new players because indeed their current squad is still able to dominate ligue 1 next season even without Mbappe, but has PSG not prioritized the champions league trophy as their main target?
The competition in the Champions League is not the same as Ligue 1, even with a squad that contains players such as Mbappe, Messi and Neymar, but PSG still fails to compete to become champions, then how will they compete for the Champions League trophy next season without recruiting good players ?