I have experience in political science, not comm, but from my very limited comm experience poli sci is a more stats-heavy discipline in general. In my entering class, which contained two master's students and six or seven PhD students, I would say overall we possessed very basic stats knowledge (maybe on the level of one, possibly two, undergrad stats courses). I had taken a semester of calculus but never taken statistics. Our program's research methods sequence was set up to start with a very basic stats course and work up from there - and it was not difficult at all.
I imagine comm to be similar; of course it probably depends a lot on what school and type of program you apply to, but all the course requirement lists I've seen include some stats-based research methods courses that should teach what you need. I haven't seen any programs that have stats prereq requirements, either.