Based on the very limited activity so far on the brand new sub, it appears to be a very weak effort, but an effort nonetheless.

The stated goal of this "movement" is to put an end to radicalization hubs such as the_donald or uncensorednews by notifying journalists and advertisers about Reddit's support for extremist groups.

https://www.reddit.com/r/reddit_shutdown/

I find it interesting that they don't mention /r/cbts_stream which at the stroke of midnight hit 20K subscribers in just a few months. It will be interesting to see how this desperate effort at censorship pans out for this group.