I have more information on BDSP. This time I have a screenshot of my second post to verify myself for those who might not believe me. I was not able to find my very first post that talked about the Arceus "empowered" forms but I think that I made it around the same time.
Anyway, here is the new information that I have.

>Full "National Dex" is 493 + Gen8 Pokemon and Galarian Forms + Legendaries and Mythicals from previous games + all Pokemon in Legends Arceus. I do not think that there are any plans to add Pokemon beyond that.
>Transfer Pokemon appear in the Pal Park like in the originals but transfer from Legends Arceus will require a patch. I do not think Alolan forms can be transferred.
>When Pokemon exclusive to Legends Arceus are transferred to BDSP, they will have a generic ability sort of like the Ultra Beasts in Gen 7.
>BDSP will have an extensive post game with a lot of side quests for the mythicals, the return of Looker missions, and then the main postgame quest
>BDSP will have an accessible Distortion World but Legends Arceus will not.
>There is are more weather effects in BDSP than in the originals. As an example sometimes it will snow in Twinleaf Town and make the city look like the Platinum Version
>There is still a very big surprise return left for BDSP. Remember that I mentioned Sycamore in my second post
>New Pokemon from Legends Arceus will be transferable to the next games but the surprise return in BDSP will be exclusive to these games. The Arceus "empowered" forms are Legends Exclusive.

Based on what I know, BDSP will be the better games even if it does not seem that way right now.