Theory For Legend Arkoos: Steel, Dark and Fairy Types won't happen!

So every knows about Pokemon Legends that's coming out next year I'm pretty sure, and how it's set in the ancient Hisui Region, AKA Game Freaks excuse to introduce Pokemon not native Sinnoh without introducing new Pokemon to Sinnoh. I noticed that in the trailers there was a lack of Dark, Fairy or Steel Types in the footage and in the most recent video Zorua and Zoroark have regional variants probably Fire/Ice from their designs. Which made me wonder where are the Steel Dark and Fairies? After scouring through old trailers and some Scholastic Books, I learnt that they specifically mention how Fairy types were a recent discovery, this could also be assumed for Dark and Steel. And since Hisui is an ancient region most likely predating the discovery of Dark and Steel Types (Possibly sometime between Red becoming Champion and Ethan/Lyra/Kris start their journeys) it would explain the lack of these types, because these types weren't discovered yet, or in the case of Steel types they don't exist yet (I just realised Lucario was in the Trailer but it had no steel moves which could point to no steel typing, it has crunch which is a dark move but no dark Pokemon were shown, I think.) It also explains why there is Kleavor rather than Scizor because the metal coat never existed, thus might suggest we could be reverting back to the old gen 1 type chart albeit with Ghost being super effective against Psychic for a change.