If the goal is to get more people health care, then letting them deduct visits for cheaper care in the country they reside in would be a
good thing. It more strain on the US healthcare system and the planet to have expats traveling back for a procedure and the deduction would be less because the healthcare cost is less.
And remember the reaction to the House press secretary Jen Psaki saying the US would provide vaccines to all Americans and then immediately walking that back when a reporter ask about those abroad with, "we have not historically provided private healthcare for Americans living overseas, so that remains our policy"? I'd say this was joke if it wasn't about the health of US citizens not getting care while paying their whole lives for it (this isn't Medicare, but still the reaction and aversion to health services aboard).