What any sane engineer would do is to keep testing these cars with a safety driver and gather anough information/miles to claim higher statistical safety than a human driver, while keeping track that those miles were really in fact driven without intervention/(or with predictable and managed intervention). Once they would have those numbers, then they would know for sure that the car is safe and they could release/manufacture hundreds of thousands/unlimited number of units to the market. If they didn't - it means either the car really isn't tested or it doesn't do what they claim it does.

Releasing a 100 vechicles just doesn't make sense, unless the claims are somehow shady or misrepresentative.