How was this secret music found in X/Y, and has anything relevant to it been found?

Question

For those of you who don't know about it, the theme has been called World Champion Battle.

Is this an actual hidden track in Pokemon X/Y, or is it fan-made music?
If it's an actual hidden track, how was it found, and has any other information about it been found?

Answer 1

It is an official track, hidden in the games.

Found in the game by a hacker. Apparently it will be the theme for the final battle of the VGC World Championship(that's where the name comes from).

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Source
Hope I helped.