Radical Arms on their Facebook page announced these will be delivered to Primary Arms on Monday. Looks like PA has set up their web site and I would imagine will show in stock once they are delivered. It will be first come, first serve. One great thing about PA is the ship normally within 24 hours, unlike our other favorite vendor with a similar name, PSA.
https://www.primaryarms.com/Complete_AR_15_Pistols_s/6686.htm
https://www.primaryarms.com/Complete_AR_15_Pistols_s/6686.htm