There is 0% chance that they sell both neymar and messi together. I believe that they are losing Mbappe anyway, so they will need as many good players as possible after such a huge kloss. If they do get rid of messi, I think it wouldn't really be a big deal, he didn't provided much to psg anyway. But, if they get rid of neymar then it will be a big problem, both mbappe and neymar gone in the same season. How would they be even able to fix that? Like who could you replace them with? I do not think that it would be possible. I think they will keep at the very least neymar, and then get another big name like Salah during the off season as well.
Knowing the boundless budget of PSG and the equally boundless ambitions of the club's owners, everything is possible. I agree about Mbappe and Messi - the first is a huge loss, and the second can be replaced by many others, he did not become a key player in PSG. As for Neymar, is he good enough to try to keep him at the club? I don't think so. Plus, if what they say about him (comes to training drunk) is true, then he harms the team because he destroys discipline.
I think that the determining factor will be who exactly will lead the club as the head coach, and based on his preferences, it will already be decided which of the players will remain at the club. Only after that it will be possible to talk about which players the bet will be placed on and around which players the game will be built. Also in this regard, the figure of the new sports director will be important, because apparently Leonardo's time in this post has come to an end, and a lot also depends on the figure of the sports director, because it is he who determines the transfer policy of the club. Therefore, I would still not rule out the option in which both Messi and Neymar will leave the club at the same time, but for now I think that this is unlikely.