Now it does, but it might not be this way in the future. Health insurance companies fought tooth and nail about covering pre-existing conditions. This is just going 1-step prior.
They could easily frame this as "hey 80% of the population who are pretty healthy -- do you like paying extra high rates for this small population of people with a predisposition for really rare, complicated diseases? if we drop this unfair law we could lower your rates by X%".
Not saying it's right or ethical, but that I wouldn't be shocked if healthcare started lobbying hard to get this tweaked.