I'm not sure I'm ready to accept the fact that having rights restricted is a body autonomy issue outside of being in solitary confinement. I commented in a different thread about "exigent conditions" which sometimes can trump personal liberties or even body autonomy when the "greater good" is concerned. If I'd entertain your statement as being on topic, I'd say that national measures in a global pandemic fit that.
I could argue the opposite. If your purported "exception" applies to 80%+ of the global population, a minimal dash of common sense would make me think that's the rule, not the other way around.
OK, don't answer that, I did my own research[1] and from the Western democracies that have mandatory military service there are: Finland, Norway, Sweden, Denmark, Austria, Greece and Estonia. They're more than I expected, and overall, including less democratic nations, there's a total of 66 (out of 194). By population it's even less, as none of the top countries except Brazil and Russia have mandatory service.
So overall that's very much less than 80%, but definitely more than I was expecting.