I highly doubt they will introduce another regional Meowth. I think GF has to know that they were already "pushing" it by introducing 2 Meowth regionals when the majority of other Pokemon haven't gotten any. To me, it appears that they only introduced Galarian Meowth because they got a particularly good Viking-based inspiration for it. I don't think it was intended to be a set pattern that they always release a new Meowth variant, and if they do it a third time, the entire Pokemon community is going to be scratching its head wondering, why is Meowth so special? If they do it a 3rd time it will almost appear to be a running gag at that point. I think they know the fans will actually be a little disgruntled by it, since it's seemingly taking up space for other previously ignored Pokemon to get new forms.
A lot of people are arguing about the logic inconsistency with introducing new forms into a region that's based in the past. Clearly, that is a logic flaw, but with videogames, logic takes a backseat to cool new features. That's always how videogames and Pokemon games have been. If they have to sacrifice "making sense" in order to make the new games extra exciting and therefore buyable then it's worth it. For example, the riding Pokemon in Gen 7. It made no sense that you can summon a random Pokemon in the middle of nowhere and hop on its back. They could have explained it by Abra Teleportation or something else easily maleable in the Pokemon universe but they chose not to, because the logic in videogame lores can have holes in it and still be enjoyable. It was meant to be an exciting feature and so they went with it, just like the new Hisuian forms, and thank goodness they did, because so far the new forms are completely fantastic. Sword and Shield did not convince me to buy a Switch but if they release more Hisuian forms like the ones they've shown, I just might.
Also I think that the Pokemon Company sort of "needs to" release new forms & new Pokemon as much as they can, thanks to Pokemon Go, which has already released the majority of Pokemon content available in the main series and will soon begin to run out of new content they can release. And if they run out of content, then they run out of ways to make money off micro-transactions. So I think it's financially important for them to cram in as much new content into any new games as they can, so Hisuian forms & evolutions are helpful in that way