I'm not super familiar with this specific system but it looks like they're using the beta release to collect more data from drivers to try and improve the learning part. This makes a lot of sense from a data collection perspective but perhaps somewhat ethically suspect.

Self-driving cars in general seem to have run into a wall as progress hasn't been as fast as a lot of people expected. The biggest issue that comes with self-driving cars is that you're dealing with something that's quite hard to predict: anomalous events. With enough data, you can handle 99% or more of the conditions you can expect to run into. It's those rare events that are hard like a child running into the street or avoiding construction debris. You can try and train for those kinds of events or even hardcode them into the system but it's not easy.

Anyway, it's not an easy problem at all. There are all of the ethical issues involved as well.