It was essentially announced, at least by MS, if not by Square. Phil told the press it was coming to Xbox at XO19:
"I wanted you to know, rest assured that we will be bringing that game [Final Fantasy XIV] to Xbox. We have a great relationship with Yoshida-san [FFXIV director] and we’re working through what it means to bring [to Xbox] a cross-platform MMO that they’ve run for years."
Then just last month, Yoshida started walking back the narrative, suggesting that FF14 on Xbox might not happen:
"I haven’t really considered releasing FFXIV on Game Pass. This is because FFXIV itself is a subscription-model game," said Yoshida. "Phil is very dedicated in his support for FFXIV, and I truly appreciate his efforts. I hope that one day, Phil and I can stand shoulder to shoulder and create an opportunity for gamers around the world to enjoy FFXIV even more."
It's such a weird situation. Basically an entire generation of back and forth between MS and Square about this game, only for it not to come to Xbox, at least if Jez is right. Square truly makes no sense to me sometimes. FFXV sold nearly 2m on Xbox One, but then they went and sold timed exclusivity on multiple FF games and Project Athia to Sony, and now they seem like they are trying to get out of FF14 on Xbox as well. Add to that all of their other games that skip Xbox, it just leaves me shaking my head.
And that's the problem. I'm not sure why MS did this. But I don't think Square was aware of it. Because if you find the latest news about it (from June 2020 I believe), Square are still "discussing".