I don't really put too much thought into what former players say about us once they depart to another team.
Particularly in their intro videos at their respective new clubs.
These are competitive athletes, part of that package requires a certain level of stubborness and self delusion.
They never transfer to another club because they weren't good enough at their prior clubs, or because as they've grown older their displays have stagnated or declined. Or even that they've moved because of selfish reasons like the weekly salary.
It's usually because they wanted new challenges, they wanted new experiences, or in cases where the departure was slightly more emotional, because they didn't feel respected enough by their prior clubs, or their prior managers weren't using them the best way they could.
That sort of mindset makes it easier to adjust to changes, to accepting the reality that with time their quality drops, and this also serves to motivate them in their new clubs. Plus, it satisfies the ego.
Didn't Torres and Macherano state something along the lines of "one day I'll tell the real truth about why I left, the supporters need to hear the truth" etc etc ?.
It's never their fault, and that's how it probably is for some of the players that we sign that are leaving other clubs.
Allow them to function.
Hope he enjoys his time at PSG. I probably wouldn't be fussed either way if he wins trophies there or not (I don't like the club). He was a solid and valuable servant of the club whilst here, respected by all his peers at the club. Won plenty of trophies for us during his time. Will definitely be remembered fondly a decade+ from now when he comes back on our screens in his subsequent career, be it in coaching or as a pundit.