This is the problem with prequels, you get stuck having to explain changes. They should have had a game where someone went back in time and changed something and now this is a while new timeline so it will not be bound to future events. Could always say the the other elves are the product of mating between humans and elves (halfbreeds), and the elves we see here are the pureblood elves. It would explain why the other elves just look like humans with pointy ears.
Alternatively, you could say that they start off looking like human with pointy ears, but as they get older they transform into what we have now. The human looking elves could be their young years and the alienish ones are their adult years.
Like I said, I like what they did with the elves, it actually makes them another species instead of just humans with pointy ears.
