There's no chance that un-vaxxed will be excluded from medicare, not before smokers and drug users are. Is there a chance that some emergency crews may turn blind eye to them (outside system rules) given a choice between attending two different scenarios, yes possible. I've heard of that happening with regard to drug users, not saying it's widespread, but one ambo I talked to was very reluctant to attended ODs in the street due to the violent outbreaks they could suddenly occur. Recently I heard that some families were violent towards an ambo crew that just wanted the group to put on masks while they treated a covid patient.
The 1 in 20 figure is actually an underestimation as it includes kids, if your an adults which we all are its closer to 1 in 10.
I was being generous to allow an overall figure, if you are over 50 it really drops to 1:5 and 1:2 quickly. 1:20 still is a huge difference to 1:5000 though.