The possibility for Messi to stay is PSG is very low and I'm sure Messi is trying to choose his next destination for next season because there is not a good situation for him in French and he can't play on a team where he can't be respected, even PSG is trying to find a player to replace with Messi and they don't have much hope about this player for next season.
Messi has zero possibility of staying in PSG. Messi is in talk with al hilal about transfer possibility once barcelona will failed to sign him back again. So many PSG fans are hating him. There's no reason for messi to stay even longer in paris. Messi shall have left from PSG as soon as possible before it;s too late. Messi has made his apologize for his mistake to do vacation without even told PSG about his plan before. It seems like that the sanction is still continuing. PSG is not willing to pay his salary when messi is still banning at this moment.
It's hard to find another messi and i think that the possible thing for PSG to rebuild its club again. They should begin by firing Galtier and then signing another coach with a good reputation to reconstruct the team.
The club is always relying upon messi. PSG didn't have a good secondary squad at this moment. Marseilla may be able to take the first spot at the end of the season.