I mean, I agree with you that the newly suggested types would be too minuscule and all that, and that Game Freak is very silly about retconning things, but I just don't really see what the issue is with Arceus. I guess I can't understand why it's okay to add the other evolution or pre-evolution method, but not another Plate.
THAT'S MISS HOME ROWED TO YOU if i'm going to heaven, i'd already be there
Really, my biggest fear with the Fairy type being confirmed is the implications that it could have on Hidden Power, assuming of course that we can transfer our old Pokemon. If Hidden Power uses a new formula to determine its type, would some of our old Pokemon suddenly change their Hidden Power type? I would cringe if all my Pokemon with HP Ice suddenly find themselves knowing HP Poison in Gen VI...
Then there's the retconning of Arceus's type plates. Are we just going to assume that there was a "Tuning Plate" that just hasn't shown up among the other 3 or 4 times we've gotten a complete (at the time) set of plates?
That sort of thing happens all the time... Take the Incenses, for example. Are we just going to assume that a new incense just magically appears so that a couple Pokemon get new pre-evolutions? Or a new item gets introduced so that a certain Pokemon gets a new evolution? I don't see people complaining about that.
I'll give you the incenses, but Arceus in the anime (I know, I know anime doesn't match up to the game) has only 16 Plates. They give out his plates in areas that are either connected to that element or connected to Arceus (assuming "The King" from Abyssal Ruins is Arceus). So why haven't we seen a Sound-based plate anywhere? At least the incenses can be created/undiscovered methods of evolution. Though the level up with specific moves thing is somewhat bothersome. But most of the time, GameFreak goes through great lengths to ensure that new evolutions can't be obtained without the help of a new method (like Espeon and Umbreon not evolving with a Sun Stone and Moon Stone). They are usually against retcons and go through a lot of hoops to ensure that very few ever appear. For what reason? I'm not sure. They just do. Not that I'd be against a new type, mind you. I just think most of the types people are suggesting are either too miniscule to be worth the trouble or are just plain stupid.
I don't mean to sound in any way disapproving of your logic, but couldn't I counter-argue this by saying that, in the anime, Mewtwo could have transformed into his "Awakened" Forme if he had felt threatened at all?
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