People know and react to its current meaning, regardless of knowing its original meaning or not.

This statement is missing the point that such thinking requires some prerequisite knowledge of the symbol. Why stop at uncommonly seen, and extremely modern usage, and abandon the well over 200 years of pre-existing knowledge?

Exactly like the swastika. Some people know its true original meaning, some don’t. But all know what it means seeing someone today brandishing one.

Still though, I wouldn't give up on the Gadsden flag so quickly. I firmly believe that as long as the average public can be made aware of how ridiculous the auth-right's using the flag is, and continues to call them out on it, it can be saved. I'm pretty sure that the majority of the auth-right, and other groups haven't considered how contradicting it is to their platform. To me, seeing someone in the auth-right flying the Gadsden flag is just as weird as if, hypothetically, a marxist decided to fly it.