I suspect they're holding back for a number of reasons, think you saw my early post about it but there's other factors too - like the element of surprise, or needed a small issue to develop further first. But I don't know, you may be right instead of course.
Phil tends to get things done and with fair sense (yes, even the false border stunt had some sense to it

), and he did make a firm announcement about doing a referendum, which I doubt he did without first preparing well.
Actually hope I'm wrong here, would prefer the referendum to be delayed (also covered earlier).