It should be noted that, as of the Crown Tundra, all of the unreleased Pokemon listed here, except for Fancy/Poke Ball Vivillon, can now have their HAs using the Ability Patch.
Of the DW and event exclusives, everything except Patrat, Snivy, Tepig, and Oshawott can also easily gain their HAs from the Ability Patch in either Swsh or BDSP.