The way I understand it anyone can sign the UGC eula and become a reviewer. The separation is probably just a way for Cryptic to protect themselves from any lawsuits, etc.
Basically, yeah. Everyone can play a new mission if they acknowledge that the mission could contain offensive stuff, so don't hold Cryptic responsible for what this or that pervert or racist did with the tools. Clicking that agreement is the only thing that separates reviewers from the entire playerbase.