I expect Mbappe to take this offer and play for them for one season. After that he can still join Real Madrid side as Al-Hilal also offer a condition like that to him. In this situation PSG will need to make a big signing. Bringing Vlahovic wouldn't be enough at all. I think they should look for a bigger talent such as Osimhen.
I read in some news said that if mbappe was feeling doubt about such an offer. Mbappe may try to stay in PSG even though he must be benched for the whole of season. Vlahovic was not enough in making the attacking line to be even better.
PSG gets draw against CR7's club. It's very bad result for PSG
If Mbappe stays at PSG for this season I don't think PSG would bench him. It wouldn't be reasonable for them. In that case as far as I know he is going to get that loyalty bonus anyway. PSG would like to benefit from his skills as much as possible in his last year in the team then. But his future is still not certain so let's see what happens. In case he surprises me and decides to stay I wonder how things will be with a team in Luis Enrique's control and Mbappe in it as well.
Luis Enrique adopts a quite different system you know. I wonder how much his control possession understanding will work for PSG in the Champions League.