I don't think the delay is from selling off old stock, but rather the time needed to develop the final production molds, boards, start mass production, and get the stuff here via the slow boat from China.
I'm part of a crowd-funded purchase of another weather station, and their turnaround was 3-4 months from final design approval to having products in the USA ready to ship. ASSuming that Acu-Rite was rushing to show the final pre-production test units at the consumer electronics trade show last month when they made the announcement, their timeframe seems to be in line with what the other weather station developers had posted.....