Yes, Microsoft put out that they're willing to do crossplatform, but they have the caveat that Xbox players would always have the choice to play strictly with other xbox players.
Yoshi-P does not want to see the FFXIV playerbase segmented by platform, so unless Microsoft waives that xbox-only-choice for FFXIV, you aren't likely to see a release on Xbox.
Edit: thanks for the fix, stitches, I was typing in a rush at the end of my break X)