The best way to protest against reddit is simply to not interact with Reddit
I see a lot of posts about how they uploaded anti-spez stuff onto reddit, or participated in the nsfw spams/john oliver spams. While I get wanting to let it all out, this ultimately keeps up engagement on reddit rather than bringing it down.
The best way to make sure things go your way? Vote with your wallet, or in this case your voice. Don't speak on reddit. Devote more time helping out the alternatives grow and flourish. And as much as it is a meme, touching some grass can help your mental fortitude.
There's a case to be made on either end. The best thing would be for people to move to better pastures with dignity, but the malicious compliance and worse create headaches and embarrassment for spez that may pay off in the press, or at some other date. Mods getting banned for making their accounts porn accounts certainly know they're going out the door, but they'd prefer to be thrown out.
And ultimately, for the veteran redditors who are watching all this, they want to see the end with their own eyes.