I wouldn't be so sure. That might've been their original plan, but things have changed. The player numbers have seen a resurgence of sorts (heh), and while the team expected it to sharply decline back to usual numbers after everyone got their Mog Bonanza weapon and things like that, well it didn't.
People are discovering or re-discovering the game en-masse and falling in love with it again. It's quite beautiful actually, and I think the team appreciates this even more.


We know that the team is working on making PlayOnline cooperate better with Windows 11. Furthermore, in the past, Mr. Fujito stated that they're actively investigating the possibility of adding new zones. And in a recent interview for the game's 24th anniversary, he mentioned looking into improvements to the graphics middleware. This could potentially allow them to make more cutscenes.


In short, while the part of the team that I assume handles stories and missions are working on another title, there's a lot of preparatory work being done to pave the way for potential story content in the future. I think that's pretty exciting!
Unfortunately I haven't found a translation of it, but this is the interview I'm referring to: https://www.famitsu.com/article/202605/75074
In the second to last question, he states that he would like to see more story content and is hoping to assign the FF11 team to produce new story content again.


If he wants to keep the game running until its 30th anniversary, I can't imagine he's going to do so with small tweaks. Or maybe I'm just overly optimistic...