Turns out, said texture owner of the main Phantom Wings isn't actually the owner.

Actual owner is https://www.planetminecraft.com/member/niccrimson/ and actual source is https://www.reddit.com/r/Minecraft/comments/82lprw/just_a_quick_elytra_texture_in_the_style_of_the/

For now, set the main Phantom Wings as the alt texture. Contact the actual texture owner.

I really liked that texture lol

Bonus: Contact Shosh because same person who ripped off NicCrimson's texture is now ripping his texture on PlanetMinecraft. Nice.

Wrong artist, Shosh99 https://www.reddit.com/user/Shosh99/ is the one being ripped off.

Update: Shosh99 contacted.