I got the email too, but immediately had a less dastardly reason that they did this after listening to the conference call today...
They said the major hurdle on M3 is battery production. They have a few automated lines and a semi automated line that got them to their capacity, and a new automated high capacity line about to be shipped to them for installation. The auto factory is doing fine.
Knowing that, I think the reason for this is simply that they can add AWD capacity after the large battery is properly automated while they bring up the short range battery production.
It doesn't make sense for them to build a different battery line until they confirm the first one works, when that happens they can bring up the second battery line a lot cheaper.
I totally get the disappointment, I'm planning on LR personally and my delivery window got pushed back four months. I'm not taking my crappy ICE car on another trip, so I guess no driving trip this summer, and pushing SR back will push more to purchase LR and put me further back still i figure. But, unless another company releases a relatively affordable long range car with a charging infrastructure, i will just wait.