Hi, Jasmine –
I wonder if the question shouldn’t be: “Why not?”
As long as the general rules about respect, kindness, content, etc. are followed, I, for one, am in favor of continuing your policy of inclusivity.
If for no other reason, the perspective of Cis people may prove to be educational, even revelatory, as we move forward in our own individual journeys.
Regarding predatory behavior, which I’m sure is one concern, it should be fairly simple to deal with offenders.
Those who are trying to misuse the site would probably not announce their presence as Cis to begin with, I’d guess.