There are plenty of rebel flags whose literal stated purpose is not slavery. The red and black anarchy flag comes to mind. If anarchy is what they want to symbolize, why not fly one of those?
More to the point, we started this conversation because you said that repenting rather than digging his heels in was why the racer in the original post got canned. Do you think he was right to be canned? If so, are you saying that repenting is a bad thing?