Theory: Maybe Pokémon could introduce Stellar cards in SV6.5 the same way they introduced us to VSTAR cards: release a product a month before the actual set they're introduced in comes out in order to provoke interest in that mechanic. We've seen it be done with Leafeon and Glaceon's VSTAR cards a month before Brilliant Stars came out, what's stopping Pokémon from doing it again with SV6.5?