Why do that when you could just get the information directly from the NHTSA [1]? I expect all those companies have been in communication with regulators from the beginning and produced plenty of documentation. Besides, they can't do the same thing the large players did since they aren't in control of developing the entire vehicle.
I read a bit of that, and it looks like the document you linked does not support the threat to fine $21k/day for not responding to the Special Order.
There is quite a lot of "voluntary" in there, along with "future regulation". I would guess that a lot of the voluntary safety assessment letters they get essentially say, "this is not entirely safe in absolute terms, but is definitely safer than an inattentive human driver."
[1] http://www.nhtsa.gov/nhtsa/av/av-policy.html