.... I am sure there could be a legal argument made that this change is discrimination against those that believe in celebrating the heritage of the south.
Of course this is “discrimination against those that believe in celebrating the heritage of the south” - so what? Governments can discriminate in countless ways legally - there are only a few exceptions (such as on the basis of race) and those are generally explicitly enumerated in law. But discriminating against those who celebrate the heritage of anything? Unless it’s a religion there’s no law against that.