>>56869837Terastral Debut was always planned, although it was supposed to happen way earlier. They sort of switched the events around. The first SV arc was supposed to be right after the group recruit Roy, and then it leads directly into the Galar arc, then they come back to Paldea for a glorified ad for SV where some of the contents would be covered like the school, the teachers, some gym leaders, and some Pokémon. They specifically said no to the SV dragons showing up also.
As for the DLC, it was supposed to be covered in a more abridged way, in fact they compare it directly to the SWSH arc in JN. However it wasn’t going to take place in Blueberry or Kitakami, but instead Paldea.
The Terapagos Shine arc wasn’t mentioned in the docs at all. By December 2022 they only had the main plot up to the 3rd Hero (Lapras), the main plot for the Rakua arc, the lore for Rakua, and minor details about the timeskip. Stuff like the Spinel arc, Terapagos Shine, and this current Kitakami arc weren’t mentioned at all.