They aren't comfortable doing pre-orders too far into the unknown future. Let them get the ones out they have sold now, get some on the shelf and build up some stock to avoid regressing into pre-order nightmare.
OK I understand but if they are not going to make more S2 units available anytime soon or at least let me know when they will be, I will turn to other competing solutions; I am ready to make a move, like, now.
Suggest you make your move, but be careful there isn't much out there that is real and affordable. Forget Hashfast, Cointerra, BlackArrow, Advanced, Bitmine.ch, all of them are either delayed, incompetent, scams or just full already.
The Chinese Dragon miners 1TH are probably your best bet, they are selling from stock, but its a bit of a leap of faith, a gamble if you like, but thats the only way really. Take a calculated gamble with one of them and see what happens, then if it works out ok keep going.