Historically "Prime" has shipped about 6-8 weeks after the initial release of a new version.
If it were me, I'd just download the free Pro demo, and I'll bet the new version of Prime will be available before your 30 day trial runs out.
Just skip downloading all the optional content, and any templates/audio you create in Pro will work in Prime. Note IF you use Effects/tools that are NOT in Prime when it's available, those won't be usable, but all your audio will work great.
I do NOT work for PreSonus, and the timing of Prime could be earlier or later than they have done it in the past.
I hope it arrives soon, but if I remember it was shortly after they get the first "major update .1 release in place", as their priority is making sure the people who have purchased have the best possible, then get the free version in place. (Sounds like good business to me...)