I can tell you what happens if only a few do it: they get harassed by their admin, possibly even fired (if they haven't yet achieved tenure).
I can also tell you what happens if everyone does it, because I have seen this, too. It's called Working To Rule. It's a classic and effective type of job action that is similar to a strike, but allows you to still collect paychecks. When we did it, admin buckled within a week. Much harder to pick off and punish individuals when the entire staff maintains solidarity.
#strike #worktorule #solidarity #union #teachers #school #education