Psychic and Fairy are essentially the same thematically since they both focus on the supernatural and folklore. I suppose Fairy, whose name is a 1 to 1 translation across regions, focuses specifically on ideas of magic and nature (ie the moon, light etc). Psychic by comparison, which is called the "Esper" type Japan giving a broader spectrum to it's application, focuses on psychokinesis, mutations, and emotion.
Like you said, the theme for the Psychic/Esper type is mutations. According to the official site, it states that: "Galarian Ponyta have been found in a certain forest of the Galar region since ancient times. It is said that they were exposed to the overflowing life energy of the forest over many generations, and this is why their appearance became unique in this region". So, if what you said is true, then giving it psychic typing was a pretty fitting choice.
And then you have Alolan Raichu who became Psychic because, pancakes... No really, that's the actual explanation they give for the type change.
It wouldn't surprise if its second typing will be flying because the Galar Rapidash will most defiantly have wings.
From what I've heard, a lot of people complained about Gen 3 not allowing you to transfer from Gens 1 and 2. Unfortunately I don't know much about this since this was from back in 2003-2004, but it seems the backlash was massive even back then. Gen 5 is largely criticised for B/W's very limited PokéDex, but it didn't get much backlash because you can still have all previous 493 Pokémon through transfer, and B2/W2 expanded the Regional PokéDex. This is completely different, because this time, the Pokémon are literally not coded into the game, whereas for every other game, every single Pokémon could be obtained in at least one way, including cheating.
Because no matter what, a large chunk of people always want to use the exact same 6 Pokémon every time.
Kinda late on that call there. Someone already posted a similar video of the same town footage.
This seriously looks like a cheap mobile game.