it'll be a matter of time before autonomous manufactures push to outlaw pedestrians and bicyclists from roadways as a 'safety measure'

I assure you that if you jump in front of a moving train you will be killed. How is this different?

cars are not trains, for one.

road usage is shared among cars, motorcycles and scooters, trucks, pedestrians, bicycles, mobility scooters, and other things.

Train tracks are also shared at train crossings. Yet if a car went there after the warning lights went on, the car would be to blame.

So autonomous vehicles should come with flashing warning lights every where they go?

Also, trains don't change lanes, or stop quickly. Its simply a bad analogy.

You are right, a better analogy would be if a person tried to cross in the middle of a random track segment. The woman didn't cross at a crosswalk so that part of road was not designated to pedestrians at all.

Cars (at lease autonomous ones) signal before changing lanes and slowing down.

I think that flashing lights is too annoying, but forcing cars that drive in the night to have lights sounds like a reasonable (and existent) rule.

The main difference is that a train, even under emergency braking, can't stop quickly, and it also can't swerve to avoid an obstacle. If you jump in front of a moving train, even if the train driver could see you before you jumped and could predict you would jump, you will get hit.