Skye, whether the patient is allowed to die or not is questionable. Non-elective care is never disallowed by most medical delivery facilities. However, the state of insurance coverage is a disgrace in this country.
In the cases you cited, not only did they have to pay upfront, they had to pay more for those procedures than the insurance companies do. Insurance companies fix the UCR (Usual, Customary and Reasonable Charges) for all dx procedures. Then they negotiate heavy discounts, as much as 65% or greater that the insurance company has to pay.
In order to survive the health care system has to kick up their pricing (the UCR level) in order to be profitable at the discounted the level insurance is willing to pay. The uninsured has to pay the full and grossly inflated UCR price.
I have seen hospital bill someone they thought was "uninsured" $35,000 for a stay. When they found out they had insurance the total bill to the insurance company was only $7,500.
That is a disgrace. Those who can afford it least, must pay far more.