>>51874576Yes, I remember that theory. It also existed in the French fandom (at the time, I didn't speak/write English as well as I do now, so I lurked on /vp/ quite a bit, but I didn't participate much).
To oppose this, I tried to explain that the name didn't fit at all. Until then, the names of the eeveelutions represented perfectly and literally their types: in French, Voltali (volt = electricity), Pyroli (from Pyro, fire), Aquali (quite self-explainatory), Noctali (comes from Nocturne), Mentali ("mental") etc...
In French, Sylveon is called Nymphali. It has no relation with metal or steel, and would be very strange for a normal type.
Nymph in French, as in English, refers to mythical creatures as well as the larval stage of insects. So some people thought it was an insect type pokémon. But my argument was that neither the shape nor the color reflected that (some said "but yes, look, it has a butterfly on its head"). But I was sure it was a new type. I was personally thinking it was going to be "magic", and I thought they were going to change the type of a lot of "psychic" pokémon to this new type, like the three elves for example. I was wrong in that regard.