Question is: How come it seems like Valve is going out of it's way to send companies stable versions (and they have not even started pre-orders yet), but someone like Elite cannot get SDK version 1.0?
Because the HTC Vive was supposed to be released first, in 2015, so of course they released the "final" version of their SDK sooner. Oculus told everyone their schedule of when their SDKs were going to be released, and 1.0 was scheduled for December, and that's when it was released, to anyone who had a CV1 prototype.
Oculus also has a much more complicated, more complete SDK with more features.