It is kind of Dissidia based though. 80 something different created beings of various fictional/factual dimensions all fighting among each other to see who is the strongest? Seems pretty Dissidia to me.

While yes, this set of fights is themed on FF5, it is very much in the realm of possibility that we will be encountering various other characters and beasties from other FF games in the other tiers. It's a clever way to allow us these "OMGosh it's X!" moments while still allowing it to canonically exist in the world of 14.