More confusing to me is the commenter who kept repeating this: "This sub’s “About” section explicitly welcomes all butches of any sexual orientation, including straight butches, and has a rule against undermining people’s sexual orientations." Then...why is it called r/butchlesbians? Another TRA takeover? (I have not kept any track of that sub whatsoever, so I don't know what's up over there.)

Also, pegging isn't a fetish. It's a fairly unremarkable sex act as sex acts go (and certainly would be completely ho-hum if both parties were biological men). But it's definitely whackadoo to think she's transphobic for having that interest, if that's what is being asserted. (Point of clarification, though: The OP's referenced tweet is about autoandrophilia whereas the post you mention is about androphilia which is just a term for attraction to men / masculine. Without the actual post text, since it was removed, it's hard to judge what was being discussed there.)

Perhaps you can fill in some of the missing detail here so this referenced post makes more sense in the context of this conversation? Sounds like your concern is legitimate, I just can't quite place it, but it's also the wee hours of the morning here.