Abortion is not a good counterargument for the modern "medical choice" movement. Because the addition of another theoretical human life that is directly affected is enough to make the question more complex, at least in their minds. I'm happy to spell out why I don't actually think it should change anything -- why body autonomy of a pregnant person is hierarchically more important than any right to life the fetus may have -- but that's still a factually more complex argument.
A better counterargument is gender-affirming care. The same people that make all these anti-vax and medical choice arguments are the ones who are blocking parents, kids, and doctors from working together to come up with a plan for gender-affirming care. Who are insisting that the state needs to step in and slap parent and doctor-approved, safe treatments like hormone blockers out of the hands of adolescents.
It's the same argument for the "parental choice" policy advocates in education. They don't really want parent choice because they don't want parents to be able to chose to have their kids taught certain materials about race, identity, or sexuality. They just want the materials banned.
The "pro-choice" crowd -- of which I am one -- should be very wary of the "choice" framing in the movement. 99% of the time, "choice" as a concept is invoked disingenuously. Maybe that's why conservatives are so frightened by the idea. When they say they want choice, it means they want any other option from their "choice" banned. So I guess they hear "pro-choice" and assume they want the option of not getting an abortion banned.