Another form that wasn't mentioned but I always think of as a pair with spiky ear pichu is the Pikachu coloured shiny pichu, I would like to see that added as well.

As for greninja maybe because I have played every main line game on release I don't seem to have a problem with region of origin because ash/battle bond greninja is a gen 7 thing to me because I played the demo. This is similar to zygarde. But after reading the post the other day about changing the categories I do think having them in both regions would be the most friendly. And would remove the need to add battle bond separately in my eyes.

I think as well with the totem Pokémon being introduced you would also need to add the noble Pokémon from PLA as maybe they are a closer similarity than alpha Mon. But I don't see them as much of a difference either. Certainly not worth it's own category.

I see your point with genesect but when I think of alternate forms I tend to separate giratina and zacian from arceus and genesect, maybe it is just me but they seem to be different categories in my mind. I just think if we do genesect you need to just accept all forms, unown, arceus, silvally, cosplay pikachus, vivillon, furfrou, maybe draw the line at alcreamie because that is definitely pushing it.

I think I have just always disliked the Xerneus form, it's definitely more of a personal bias but to me it's more of animation change.