This isn't really true unless you consider feminism to be all the things that every person cumulatively refers to as feminism today. The radfems have always been anti-man and this exact reason is why they became the canary in the coal mine and then the front lines against TRAs. They are rooted in second wave feminism and are advocates for women's only spaces which was one of the core issues of the second wave. At the time there were often no bathrooms for women in public places and women who left the home were often harassed by men who treated them as sex objects.

The most toxic transgender people are the autogynephiles. They are sexually aroused by seeing themselves as their idea of an "ideal woman" which is basically just a mindless sex doll. These are still heterosexual men who are going to threaten women's privacy by gawking at them in the toilet with a weird sexual gaze. Radfems were second wave feminists who became rather extreme in their anti male bias and defense of women. They ended up slamming head first into the TRA autogynephiles a good decade or 2 before anyone else had caught on.

All the people today espousing 3rd and 4th wave feminist ideas are almost antithetical to what a 2nd wave feminist was fighting for and this part isn't really surprising because TRAs are best at parasitically stealing credibility from all other movements. Yes they stole terminology from intersex people and stole history from gays, but they also ran off with feminism. The AGPs in particular were obsessed with being feminists because it was another layer of being a "woman". This whole field of intersectionality is about proving how MtFs are even more important in feminism because they can layer all of these labels on top. They took the antimale terminology from 2nd wave and spun the exact same words to be about transgenderism.