CL follows US Fair Housing law for US listings. They may treat roommate vs. full-rental listings differently, see:
Shared Housing Exemption -- If you are advertising a shared housing unit, in which tenants will be sharing a bathroom, kitchen, or other common area, you may express a preference based upon sex only.
https://www.craigslist.org/about/FHA#roommates
It may help to post to rooms and shares specifically.
You may get more appropriate feedback through CL's own support forums (moniored by staff:
https://forums.craigslist.org/?areaID=11&forumID=9
Community housing discussion (user-discussion):