I remember that Xavi said (even when he was about to quit) that he needed a break of a year in order to rest and recover. Plans may change, but probably for this he must receive some interesting offer. With all due respect, he has not yet outgrown the status of a “beginner” coach, so it is unlikely that he will receive it, he needs to choose some ordinary club to prove himself or wait for the mood to change in Barcelona and return there.
If he leaves now, coming back to the club is not certain for him so soon. Going for at least one year leave to at least retest his strategy and be perfect will not make Barcelona to sack their existing coach when he decides to come back and coach the team for another time. When he leaves now, his coming back won’t be going to coach Barcelona directly, he must test his strategy with younger teams and his quality and success rate will now determine whether he’ll come back if they need a replacement at that time or not.
Barcelona might have added to his poor managerial skills this season as seen by the management of the team, although i see this season as not a too bad one to want to sack him. He just win the league last season, given him more time wound have been better but they despise him to have him go get another job elsewhere. Xavi will still be wanted by many clubs after being sacked because his strategy will work well for some average teams and nit for big teams like Barcelona. He should try his luck elsewhere because i see flawless victory and success awaiting him soon.