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There was a leaker on Feggit with a legit corp newsletter as proof who said that they would release Johto in LGBT through trading to your new Gen 8 game. But you'd basically need two Switches to get this done, thus it's less a free DLC and more a $350 expansion.
He also said as of Nov 2018 they were not finalized with all the new Pokemon, but that they were hoping to decrease the amount of legendaries in this new generation.
He did say they kept the Pokemon designs very secret and teams were only given typing/codenames, description of what the Pokemon looks like, no images for the teams that write Dex entries and decide stats. This is why Vikavolt turned out to be so slow and explains other mons.