The problem is that I'm not sure they will EVER change their tune until patriarchy is completely dismantled. They will act in their group-interest in much the same way liberals with enough wealth will act in their class interests.

We can create class-traitors but we can't effectively achieve a change among them all without eliminating patriarchy altogether, at which point there will no longer be a "class interest" dynamic among the cis white men and they will no longer defend against the loss of the privileged position. They will default to the new normal social organisation of no-patriarchy existing at all.

Unlike with economic class interests there's also no solution rooted in accelerationism or various wealth groups in society growing/shrinking or the kind of situation where it might be hard to achieve socialism in the core but easy within the periphery where class interests differ greatly. It's an absolutely monstrous battle when you consider it in that way and I suspect the ONLY way to resolve it is simply by authoritarian smashing of the patriarchy to establish the new norm and no amount of struggle will change people's minds to make them all go against their social-interests.