Studio One v6 was released on 9/29 by Presonus.
Presonus ran true to form on this release, like they did on v5, by not making the demo or Prime versions available right out of the gate. IIRC, the demo and Prime usually follow the Artist and Pro releases by about 10 days to 2 weeks. I was told the reason is that their servers get completely overwhelmed with upgrades and new sales for about two weeks after release. Coupling that with freebie downloads would probably put them completely off the air.
I haven't upgraded to v6 yet, as I have some other things going on for the moment that take priority. But without a doubt, I will upgrade to it when I have time to dedicate a day or two to deep diving into the new features.
I checked with a friend of mine who works for Presonus support and confirmed that they aren't currently available.
Unfortunately, all of the customer facing section of the website where you could select and download the V5 demo or Prime are no longer online and return 404 (not found) errors from their server.
As soon as I find out that the demo and Prime are available, I'll post it here in the recording section.