Alright, so more people have healthcare under this plan as it forces folks to buy insurance from certain providers. This means demand increases, but what happens to supply?
One of my professors who taught some topics on reinsurance made it clear to us that folks who have insurance would only take more risks. I forget what he called it, but it is some principle in insurance topics. Since this sort of risk is prevalent in today's society, it means that pricing models for insurance products would only increase in value over time. And as such, so would costs.
Supply really isn't an issue. You can be insured for just about anything, the issue is cost.
Risk does play a part in health insurance. However, what you're talking about is an exaggeration. I'm on insurance and I would play rugby, go backpacking, etc when I wouldn't when I wasn't insured. That's what the majority of people do. Most insurance rates aren't based on risk unless someone is a professional athlete, daredevil, etc. Average risk isn't something that's quantifiable considering it's relative to the individual and most insurance policies are purchased through the employer as a group. There is risk involved in every policy, that's why you pay a deductable before most insurance will begin covering you.
The larger issue is wellness. The more unhealthy your co-workers are, the higher the insurance cost. My dad's lawfirm has 2 people that survived cancer, so their rates are rather high. They go with my mother's because she's a VA nurse and it draws from a much broader, less risky pool. Looking at an even broader scope, the US is one of the least healthy countries, so costs are already expensive.
Another thing to add in is the cost of uninsured treatment at hospitals. Prices of procedures, tests, treatment are generally based on the amount of uninsured patients seen by a hospital. The more insured patients a hospital knows it will receive the lower the cost.
And we just lost to UCONN.