This is the unmodified asset of the first version of the Reforged Night Elf archer that I have on my computer in my backups. She stands a little differently than the release version of the Night Elf Archer, but she is still a bit of a hunchback. I noticed that during her walk animation her cape animates in a way that makes it look thinner, and this causes her to look taller.
So, for more background on this model, for a long time I believed there was a secret Reforged Beta build that I forgot to back up that had the "upright standing" version of the Night Elf archer. I even said to one guy in a private message:
I don't think I have Night Elf Archer
https://wow.gamepedia.com/Warcraft_client_builds
If we look at this list of client builds
Between Build 13594 (that I have) and Build 13769 (that I have) there is
only one build
And this is Build 13680. It released on November 13, 2019 and was replaced exactly one week later on November 20, 2019
Everyone had exactly,
and only 7 days to save a copy of this build 13680
But as I looked into this further, I have come around to the idea that there is not a publicly released Night Elf Archer model that I don't have. Instead, I was just remembering this one, and maybe some pictures of some Blizzard teasers of their internal alphas or something.
Here's another link that appears to support my theory -- this post is all written as though they had datamined the Night Elf assets at the time of posting -- and even at that time, their Night Elf Archer model that they are previewing is the same one I am uploading here.
https://www.wowhead.com/news/night-elf-models-from-warcraft-iii-reforged-tyrande-malfurion-faerie-dragon-296403?page=4
Edit: For posterity, I also included an archer model I got from IQueen who said he got it from Symphoneum that is a fan-art of an upright standing Night Elf Archer, created probably by using Sylvanas Windrunner animations.