No, these people were always sexist, that's why it's so easy to hook them on this bullshit.
We are all socialised with misogyny (as well as cis-heteronormativity) literally from infancy (and those of us who are directly impacted sadly internalise them to a depressing degree), and that's when we need to start fighting against it, not only once the misogynists turn violent (verbally as well as physically), it's too late at that point (even if they can be deradicalized the damage they did is already done).