>>19177642There'd probably be very little work involved, all the models, code, textures and sound-effects for all the pokémon are already done, since there's likely not going to be any new pokémon, they could literally copypaste the entire feature from X/Y into the new game and it'd be pretty much done, maybe reskin the interface or tweak the facial recognition to work better if they feel like putting in an effort (but I'll honestly settle for Ctrl+C, Ctrl+V port of it).
