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If GF doesn't do it, Fans will. Pokecheck already does it for Gen 4 to 5 transfers.
Someone will make a Pokecheck type thing that you upload your 'mons from Gen 5 via a fake GTS, and then download them in X/Y via a fake GTS, converted to Gen 6 format. Will some stuff change, like their Hidden Power? Probably.
Whatever reason that GF is having difficulty, fans will find a brute force method of forcing a Gen 5 'mon to be a Gen 6 'mon. If GTS existed in Gen 2 and in Gen 3, you better believe this fan made shit would have existed.
