Earlier quoted context omitted.
To be fair, a lot of stuff work that way. Take an HVAC maintenance plan for example. For some fee (based on the model and age of your HVAC and the condition it's in), you get routine maintenance covered. They do what they can to prevent major hiccups, but if it breaks down, they'll repair it (after trying to weasel their way out of it). It's pretty darn common across a lot of industries.
There's a pretty important difference between humans and HVACs, which is the reason the two systems end up being very different. You can always rip out the HVAC and put in a new, off the shelf unit with roughly the same specs (often better, because progress) at a fixed, known cost, and the customer will even often be happier if they end up doing that instead of repairs. If health care providers could trivially decide…
All i was saying is that it's pretty common/normal/etc for insurance (in any industry. Literal insurance or things that are insurance in practice but not literally) to offer routine exam/tests/maintenance/checks if it can prevent the worse case scenario $$$ from happening.