In that location, I'd first though it was one of Google's vehicles But why the Nevada plate? Turns out this is Embark.[1] They even show their AU 0030 license plate in the video.
Embark has been testing in Nevada, where the regulations are looser and there's less traffic. Their demo video is on a a deserted, straight two-lane road, closed for the occasion. Good place to debug.
Embark isn't on the list of CA DMV autonomous vehicle test companies. Also, CA won't allow autonomous vehicle testing of vehicles over 10,000 pounds, figuring that if something goes wrong, it's better to have car accidents than heavy truck accidents.
When Otto did that "autonomous delivery" of Budweiser with a semi, their vehicle was surrounded by chase cars. It was a much more controlled environment than the video indicates. There's too much "fake it until you make it" in this business. Waymo and Volvo are building systems that can handle unexpected trouble. Some of the others, not so much.