Final Fantasy 14 devs just went ahead with their FF9 homage because otherwise they would have been "waiting and waiting" for the rumored JRPG remake to show up

gamesradar.com:

Final Fantasy 14's Naoki 'Yoshi-P' Yoshida has once again put some distance between the MMO and the long-rumored Final Fantasy 9 remake. In a new interview, he reiterates that the MMO serves as a Final Fantasy theme park and that FF9's inclusion is no different from other series entries.

Earlier this year, Yoshida turned some heads during a PAX East panel when he revealed that Final Fantays 14's Dawntrail expansion would come with a few FF9-related goodies like minions and a popular summon turned into a mount. "You may have noticed a lot of Final Fantasy 9 references here," he said on stage with a smirk, "but the reason is a secret."

Final Fantasy 14 featuring nods to other games in the series isn't anything new, though the swirling rumors around Final Fantasy 9 getting a remake got people's attention. That, and comments about two unannounced games we'd hear about "soon." As such, Yoshi-P clarified in a later Live Letter stream that FF14 dev Creative Unit 3 isn't remaking the beloved JRPG, nor does he know of a remake at all.

Now, when asked if it would have been better to wait for a Final Fantasy 9 remake to be announced before teasing those crossovers, Yoshi-P points out that the team would have to wait for that to actually happen, and that the scale of remaking the classic JRPG means the team could have been waiting a long, long time. 

"So, the original concept that we had for Final Fantasy 14 is that it serves as a theme park for the Final Fantasy franchise and so we wanted to incorporate Final Fantasy 9 because of that," he tells JP Games. "We had never thought about doing Final Fantasy 9 in relation to any sort of 'Final Fantasy 9 Remake' – we had never thought about it in that commercial sense. Of course, it might make sense to think about it that way, but we never have.

"But of course, in our development team as well, we have a lot of staff who are huge fans of Final Fantasy 9. And – as you know – Final Fantasy 9 has huge volume, it’s a big game. If we were