But I'd just add there is a pretty major difference between "temporarily" and "permanently". Major kudos to r/ProgrammerHumor and other subs that are doing it right - saying they will be shutting down indefinitely unless Reddit changes their stance.
Just saying you're only going to shut down for a couple days is essentially theater - Reddit can certainly wait out some popular subs being down for a few days. More generally, that's really the only way protests have a way of achieving their goals, by saying you'll engage in some behavior (or boycott) until your demands are met, or at least met with some change. Anything that's time limited is pretty much doomed to fail. For example, I'm not sure what the organizers of the recent Amazon "walkout" hoped to accomplish. That wasn't a walkout, it was lunch.