It’s my understanding that in addition to the cameras it also uses the sensors already built in to the car which would include blind-spot detection, no?
Some cars that have BSD it will work with. My car uses it, but don't forget the lane changes are not automated by default. A user must turn on the blinker and nudge the wheel by default. Positive BSD sensors read on CAN-BUS will be read by OP and it will not perform the rest of the lane change. This is how it works on my car (albeit, I don't run default so I just need the blinker).
It says my car is supported and my car doesn't have any blind-spot detection, nor does the requirements list that as needed, so maybe it's optional but not required?