Steve,
Thanks for your post about the service bulletin.
My local servicing GMC dealer had my Sierra for about a week.
This was the 8th time it was in for the blue screen " service rear camera".
In previous services they had reprogrammed the computer multiple times and done at least 6 updates with No Joy.
I would drive out and within 2 or 3 start cycles it would be back, but not always present.
This last time they claim to have changed a module behind the rear seat.
So far, one week later, no blue screen.
I hope this is it.