The Gen 8 regional dex is the Gen 8 FINAL dex. There is no national dex. You WILL NOT be able to have every pokemon in Gen 8 post-game. Additionally, the new Pokemon Home cannot move your transferred 3ds pokes back to 3ds.
Their reason for this change?
>Competitive balance
(which GF never cared about)
>and focus on high quality game
(just look at any WEBMs from e3, not quality at all)
/vp/, reddit, resetera, twitter, AND the normies are revolting, all for good cause. Remember that favorite pokemon you've had forever since gen 3? It cannot exist in Sword Shield. It isn't coded in the game.