Oh, I was incredulous because I’ve never even heard something like that online, where people will share some truly out there opinions.

We seem to otherwise agree on stuff.

Your last paragraph kinda highlights my bonus reason for disliking mras. They’ve made it nearly impossible to think of a space where you can discuss mens issues that isn’t at a baseline antifeminism.
Patriarchy hurts men as well as women. Addressing how it hurts men has the opportunity to help prevent future harm, like by helping people figure out a definition of manhood that isn’t everything wrong with modern masculinity, which can be hard if you have next to no examples to show you it’s even possible.
It’s not feminists as allies, it’s feminists talking about a different part of the conversation.
Mras are so toxic that it’s become legitimately difficult to convey “I’m concerned with how society messes up men” without people thinking you’re about to segue into some misogynistic awfulness.

All that to say, blaming feminists for circumcision is a type of delusion so far out there that I have trouble even conceiving how you would do that.