Blind spot monitoring was so very, very good that they removed it from subsequent release notes and sales promo materials and placed it in the memory hole.It was. It is. Using the ultrasound only. Again PER THE RELEASE NOTES (please read the blog post)..... this version ADDS cameras in addition to the ultrasound to make it better. Also adds the line going red if your turn signal is on. This addition to cameras is obviously AP 2.0 and up because - well - AP 1 doesn't have side rear-facing cameras.....
The blog from Tesla is very clear and quite informative.
I'm just amused that three years later, there's some confusion (per the original post I was responding to) whether it even existed at all.
EDIT: I'm happy blind spot monitoring is finally there. I paid for it. I've driven 25,000 miles. I don't have it. Let me vent.