“Guy” is also gender-neutral for me. When approaching other girls, my normal greeting is “hey guys!” Saying “hey gals!” is...an off-putting notion.

“Gal” instantly conveys a long-gone era of disempowered women to me. In an era of non-binary genders, I think reclaiming it would only serve to further exclude. Rather than try and force the world to use a new gender-neutral word (“zer”?) just let “guy” be the gender-neutral word it has been used as for decades. It doesn’t have the gender connotations of he/she/him/her and needs no correcting.