He doesn't have a choice really. With the PR mess he got himself into, no big company will ever hire him. Imagine the possible headlines "Microsoft hires the James Damore, the male supremacy advocate fired from Google". Nope, regardless the technical skill or his actual personality, his public image is forever ruined. So he realistically has a choice between becoming a paid speaker for fringe ultra-right organization…
No that just isn't how life does or should work. You make mistakes in an industry and you own the impacts to your reputation. He has done serious harm to the work of so many by his actions and absolutely deserves to own the consequences. And let's be serious here he has zero chance of winning against Google.
Initial filing for a court case is crucial for establishing what we're actually sueing over, and this will be an interesting one, because the chances of his legal team winning this one are definitely non-zero.