And calling for ethnic cleansing or genocide isn't really a direct threat. After all, Neonazis have assured the American public that they're only after "peaceful genocide" and seeking their ethnostates by "nonviolent" means. (This is not a joke, by the way.)
At the time of my posting, I was incorrectly assuming that the OP was talking about a ban of Nazism in general using the flag as a stand in, and did not realize yet that they were talking about literally only banning the flag and nothing else.
Sorry for that misunderstanding on my part. I agree with you that only banning the flag would be rather daft in that context.