Always vet potential roommates independently. Meet in a public place first, and if possible, ask for references from previous roommates to ensure the person is legitimate, even if they found you on a niche site.
If you are a trans person looking for housing, this should be one of several tools in your belt, but not your only one. It is an excellent place to find "safe harbor"—landlords or roommates who are explicitly allies or part of the community. transroommates