Bump...
https://www.serebii.net/news/2023/30-May-2023.shtml
Good news is that according to Serebii we finally now have Pokémon HOME connectivity for Pokémon Scarlet and Pokémon Violet even though they probably could've waited until the new DLC dropped later this year while also having more time to patch the games which is consequently creating new bugs within the games. They actually added some new features this time around by moving the Move Reminder to Pokémon HOME and the ability to tab between different game data for Pokémon on the fly. There are now over 70 Pokémon and dozens of Regional forms coded into Pokémon Scarlet and Pokémon Violet that are Transfer Only:
https://www.serebii.net/scarletviolet/transferonly.shtml
That means that they're not listed in the Paldea Pokédex but still useable in game and can only be transferred through Pokémon HOME or various event distributions. There is a new restriction. If a Pokémon obtained from Pokémon Brilliant Diamond and Pokémon Shining Pearl are Hyper Trained in Pokémon Scarlet and Pokémon Violet while under Level 100, it cannot re-enter Pokémon Brilliant Diamond and Pokémon Shining Pearl until it is Level 100 again. The biggest change so far is that the game no longer tracks abilities between games. If you move a Pokémon to a different game and give it an Ability Capsule or Ability Patch then that data only remains for that game.
For example, If you move a Charmander with the ability Blaze from Pokémon Sword and Pokémon Shield to Pokémon Brilliant Diamond and Pokémon Shining Pearl and use an Ability Patch to change it's ability to Solar Power which is it's hidden ability, when you move it back to Pokémon Sword and Pokémon Shield and Pokémon Scarlet and Pokémon Violet, it will have the ability Blaze but If you then move it back to Pokémon Brilliant Diamond and Pokémon Shining Pearl, it will have Solar Power in that game. Also there doesn't seem to be any reports about not being able to transfer Pokémon onto Pokémon Scarlet and Pokémon Violet that have been permanently Dynamax Leveled in Pokémon Sword and Pokémon Shield which is a big concern I've had for awhile now.
What really surprises me the most about this is that the Transfer Only List didn't even include the returning Pokémon that will be available for the upcoming DLC expansions for Pokémon Scarlet and Violet such as Milotic, Shiftry, Yanma (no Yanmega?), Kantonian Ninetales, Dewgong, Metagross, Whimsicott, and Politoed. Politoed I was actually looking forward to as a viable backup for Pelipper in Rain Dance / Drizzle Teams for VGC. Unfortunately Alolan Ninetales didn't make the cut for returning Regional forms in Pokémon Scarlet and Violet since she would've been amazing in Snowscape Teams for VGC. So I'm not really sure what Nintendo / Game Freak were thinking when they didn't code in the DLC Pokémon along with the rest of the returning Pokémon on the Transfer Only List.