Day6- again you are confusing several things here. People who travel as tourist, those who come from outside the EU/EEA and those who are RESIDENT in EU/EEA- and became so, having carefully researched that they would be able to access reciprocal health care (here in Switzerland we have to pay the first 300 Swiss Francs each year, then 10 % up to 700 CHF- so about 1000 per year. There is no way of covering this with top up insurance.
Your comment 'Those people living in Europe will have to consider their options.' is quite correct- and this is what is causing so much stress, fears and worries. As per the article quoted. I imagine those already in the system in France will be OK, at least for a while. But it may well become much more difficult, or even impossible - if we drop out without a deal.
But since you said that the NHS is not a bottomless pit (and I agree there) - do you think that 1000s upon 1000s of British retirees in the EU/EEA having to return because of loss of healthcare, will make this better - or indeed much worse.
Notwithstanding that they would return having lost more or less everything - and would be in need of housing and social support?