I hear that he won't extend his contract because it seems he doesn't enjoy the city of Paris. I doubt this. Is he going to move back to Barcelona, I don't think so. How do I know? I don't. I just feel that it will be a wrong move and if he does it, Barcelona will not do well anymore because it will seem like he is taking the shine out of the other players. He may like Ronaldo move to one of the teams in the Arab league. I may be wrong with my analysis and deduction but that is what I feel.
with Messi's bad situation at PSG, I think the best option is not to renew the contract. and that means he must immediately find a new club for him this summer.
it is not impossible that Messi will return to Barcelona, although there are many considerations that will be made. but if there will be a better offer from another club in the Saudi league like what happened to Ronaldo. or from other European League clubs. Messi will not refuse it. Messi has skills above the average player now. his current enemies were only age and injury shadowing him. he just needs to find a club that believes in him.