It really depends on context.
If she is a virgin (or has only been fucked by you) then it is not beta to eat her out.
If she is a non virgin (and has fucked other men) then it is beta as fuck, you're eating out a hole that's had Chad's cock and cum in it
If you eat her out, but you find her vagina unattractive, or she forces/pressures you into doing it, then it is beta
It is not beta if you eat her out, because you want to, and she has only ever fucked you (or is a virgin)
The whole "it's cucked to eat out a girl br00000, it's giving her pleasure without pleasuring yourself br000" is cope
It can get both of you turned on, who the fuck would want to fuck a dry pussy? No one. So get her excited, and she'll have that shit wet as fuck by the time you're ready to slide in