Virtually any choice you make in life has some type of health care risk. I think that's almost impossible to draw a line and say these behaviors are ones we will deny care.
The proposal is to separate people into two groups: those who agree to donate their organs, and those who decline. Later on, when people happen to need organ transplants, they receive them according to their group priority, i.e. if you decline to donate, you turn comes up only after everyone in the first group received their organs.
I think that is a fair system, and could be applied in this case also. If you choose to vaccinate, you are covered, and if you do not, you pay out of pocket.
If everyone gets vaccinated, and 1% fail (that's just an arbitrary number), it's no big deal because there isn't enough of a population to carry an outbreak.
But if 1% of vaccinated patients are vulnerable, and 5% of people choose not to get vaccinated, then now there's a potential for outbreak, and even some people who vaccinated get sick.
In economic terms, by not vaccinating you're introducing a negative externality into society that you're not paying for, so the true cost to non-vaccinators is artificially low.
Not really a flaw in your system as much as just something interesting to think about.
Hold it. If you're going to deny them govt-paid healthcare, how do you justify taxing them to pay for govt-paid healthcare?