Is there US governmental oversight of this program? Or is it just a business arrangement between numerous copyright holding companies and ISPs? It looks like the latter.
After an end user has received all 6 strikes, they could be sued or the ISP could cut them off. Nothing prevents someone from being sued before completing all 6 strikes, and a user could possibly complete 6 strikes and receive no penalty.
It has been specifically designed to avoid regulation. The ISPs opt-in, there are no prescribed penalties, there are no legal notices or anything that would involve the courts.
The Obama administration did play as a "mediator", but you're right. This system is specifically designed to avoid regulation, because they know they wouldn't get that regulation. This way they can sidestep it by "partnering" with the ISP's and carriers.
After an end user has received all 6 strikes, they could be sued or the ISP could cut them off. Nothing prevents someone from being sued before completing all 6 strikes, and a user could possibly complete 6 strikes and receive no penalty.
https://en.wikipedia.org/wiki/Copyright_alert_system