Choice starts prior to your timeline.

If he doesn't want to wear a uniform don't apply.

If he doesn't want a possibly of being forced into a captain upgrade, don't apply.

I mean it's not like applicants won't know the rules before hitting submit on the application. You might have a point if the current pilots weren't protected. My question/thoughts are not analogous to , "If you don't like it quit, SW, AA and DAL are hiring"

Quitting is forfeiting seniority. Re-prioritizing your "dream job" prior to be hiring is assessing current conditions. To me, they are different.