Kotaku cites unnamed sources for this revelation, but notes that "two different developer sources" had linked the now-canceled game to the Japanese side of publisher Square Enix. Furthering that tenuous connection, the site points to a recent OXM interview with Lightning Returns: Final Fantasy XIII gameplay director Yuji Abe, in which Abe suggests that Square Enix might one day allow Eidos to develop a Final Fantasy entry.
"Obviously, Square Enix bought out Eidos a number of years ago, and now we have direct access to American development teams," stated Abe. "That's certainly been discussed within the company, the possibility of say, Eidos or maybe someone else to look after or maybe take on the Final Fantasy series."
Was this canceled game a new Final Fantasy entry? Did it even exist? We attempted to contact Square Enix for more details, but never received a response.