It feels like they've been out of the Prime forever. It was out of stock when I ordered my Stellar early this year, and I'm not sure if it ever went back in stock since that time. The Stellar has usually been available, though. This is the first time I've seen them both out of stock.
Anyway, I called the number on that order page, and spoke with a friendly guy named Jim, I think. He said their best guess was that they were three weeks out from getting fresh batches of both the Prime and the Stellar. I asked if they would continue to use Alps switches, and he reassured me that they would stay with mechanical switches.
I realized later that his phrasing left them an out to change from Alps to another line of mechanical switches, but I didn't press him on it. I think he merely wanted to extol the virtues of mechanical switches over membranes. Besides, if the Avants stop shipping with Alps key switches, they'd be betraying their Northgate Omnikey legacy. And I don't think that's going to happen any time soon. At least I hope not.
I noted that the web site said that the Steller was "now shipping in black" and asked him when they had changed colors. He said this new upcoming batch would be the first black Stellars. A decision of their marketing people, he said. He asked how I felt about the change, and I said I acutually preferred the all black scheme. (I didn't mention that I appreciated black all the more after spending two days with the hideous two-tone silver and black of the SMK-85.)