>>50632312I think it's going to be Dragon if they do anything, because it's the last of the original special types and is a good partner to Sylveon since the previous times we were introduced and evolutions that came out in "opposite" pairs. But
>>50633041 brings up a good point which is that they have said multiple times the artists are not allowed to look at fan art and they are not entirely supportive of the fakemon because they are afraid of having their ideas tainted. Since Eevee is such a popular Pokemon they're going to have to come up with something, but it's going to be difficult to have it be totally original especially in a post Sylveon world.
If I had any money to put down, I would actually say we get a weird regional form(s) or finally get the Normal evolution which is something people often don't make fanart of
