XI is never getting revived. What charm the game had is long gone for her stalwarts and what made XI was the community that curated her wiki entries, delved into questions like "meat or sushi?", the HNM hunger games, the long inhuman grinds, the waiting for years for QoL patches, the small glimmers of success when you finally stopped getting fucked by the system etc etc.
That's finished. I'm hoping whatever successor can do Vana'diel proud by keeping the themes, characters and job system alive. That's all I care about these days.
As for P2P MMOs? Look no farther than XIV. You're being asked to pay monthly but you could very well stop and start at any time and really miss nothing. Play a month, devour all the casual content, ignore the hardcore raid scene then come back when that's all invalidated and start the cycle anew.
Today's MMOs make it pretty easy to start and stop if you're not interested in being at the cutting edge all the time. And unlike XI they make it clear when you're constantly junking gear.