Cetainly if we still know what it means today, it could still be used by some folks 200 years from now.
Anything might be true 200 years from now. "Sawbones" is archaic now, and there's no real humor or wit to be derived from using it.
This is one of the most time-wasting aspects of fanon - some people become so attached to their expectations and assumptions that rather than being pleased when some aspect of a story surprises them or goes in an unexpected direction, they become protective of the assumption and in some cases invent some fairly closely-worked out rationalizations for why the writers were
wrong to do what they did. I watched idiots do this with the later seasons of "Buffy," which was particularly sad because that series was
so energetically off-kilter and counter-intuitive all along and would have been a lesser show without that quality.