I think it's a totally separate project from Infinite Undiscovery -- ID is a single-player game, whereas the one Tanaka talks about is a MMORPG, unless it changed into ID during its development? There's separate Wikipedia articles for each game too.
The best evidence I can readily find regarding FFXI's influence on the Chrono franchise is this quote from Richard Honeywood:
Final Fantasy XI is pretty much it for a while. We still have a lot of possible expansion packs we could do, and plenty of support to give. As far as Chrono is concerned, that's huge; but we can't do two or three things at the same time, and it's tough to do FFXI and another Chrono game at the same time or too close together. We'd love to do one though, but yeah, not yet. (2003-05-14).
That's from the Chrono Break Wikipedia article. If members of the "Dream Team" who were tied up by FFXI also get tied up in this new MMORPG, it's good bye Chrono for the time being, again. Hopefully I'm wrong on that, and hopefully this doesn't answer brifye's question above.