Omg... i just saw this and i'm flipping really hard.
First.
Tattoos, athletic builds, hairstyles and being away from the sunwell are all valid asumptions because:
A) Tattoos and Hairstyles does not break any lore, in fact, those are pretty probable, the first the less probable and the later the most.
B) Athletic builds: This is a way to say we would accept another type of body if that helps, we are not sugesting elves big like orcs, not even like humans, but even more or even less than BE, or by defect, another idle like Blizzard did with Nightborne.
D) The Sunwell: Elves are pretty sensible to magic, you can even see that the HE does not even have glow in their eyes, just color, the new HE could have a different and even restricted palette of colors such as black hair, white hair, lightly blonde or grey, and pale and not-so-pale skin colors, idk, is not in my hand to decide and the last word in this is Blizzad's, but what is truth is that this is warcraft elves we are talking about, and magic plays an important role in how their bodies and looks work.
What is headcannon is inventing a situation in where High Elves are neutral and they decide their allegiance, when the lore never was like that, BE didn't joined the horde right away, and even saying that HE are a neutral race, when they not compare to Pandaren in anything of the sort.