Let's not kid ourselves, like all of the previous productions, Fuller is going to keep/jettison stuff from the Prime Universe as he sees fit, to the point that I'd bet a lot of the people currently happy about it being in the Prime Universe will be bitching about how STD ignores canon in a year's time.
Yeah, I'm envisioning something like the new Doctor Who, where it was supposed to take place in the original continuity, but was so far removed from it that it could have been the same universe in name only. (Granted, this changed over time, but that's not how it started.)