Psg has a stock of great players, but even so, Luis Enrique also fielded their main squad when facing Revel so that a win with a big score was the final result in this match. Revel is not a strong team and their defense is so fragile that Mbappe et al had no difficulty scoring many goals in this match. Indeed, this is quite a big risk when facing a non-seeded team, but they play with their full squad so if an injury occurs to a player it would be quite a shame.
But this match provides strong evidence that the players are able to play more carefully and they are able to do well because nothing bad happens to them. And there are no other matches this week before Ligue 1 starts again, so PSG players get plenty of time to stabilize their fitness to compete in Ligue 1 matches.
It is not simple to give this kind of games meaning to be honest. On the one hand you see big clubs fail against those teams because they don't go all out and believe that they can win the game easily when they perform at 80%. On the other hand I recall that Bayern Munich was defeated by a team that was playing several classes below them in Germany. It wasn't even 2. Bundesliga I think and yet Bayern Munich lost the game. So it was a good job by PSG to approach this game with high focus and intent to win it, but simultaneously nothing of importance really happened here.