I'm in the same boat as @Trips and @quantumslip - Ordered in-store 3/31/16, configured online 5/23/18, still no estimate given beyond the original 12-16 week delivery timetable when placing my configuration order. I'm hoping they stick to that 12-16 weeks, otherwise, it seems as though there was no benefit to ordering a month ahead of everyone else.
I think the May orders will get their vehicles a few weeks earlier in most cases. There were only about 10,000 reservations that qualified for the May AWD invites. If 1/3rd already ordered the RWD and 1/3rd are waiting for the SR that would leave about 3,500 P/AWD orders in May. They should get through that pretty quick.
I really think it was to see how many people would order the Performance vs. AWD. The percentage of Performance orders might have came in lower than expected so they decided to change up the options available for the June orders.