alt Hacker Newsthere is already a swastika unicode glyph. As for the Confederate Flag, they will probably be confused as, if added to unicode, it would likely be rendered as one of the actual confederate flag designs rather than the one which has become popular in recent decades.
> there is already a swastika unicode glyph
It's a Chinese character and there are two variants. The left-hand variant (卍) represents 和 (peace) in religious contexts, whereas the right-hand variant represents 力 (power). The specific glyph the Nazis co-opted is the right-hand variant, and it is considered inappropriate to use in the West (for this reason, I am not reproducing the character here).
The glyph appears in texts predating the existence of Nazi Germany, and I assume that is the reason the Unicode Consortium has not removed the glyph yet.
Note that I am not defending this decision (nor the usage of the glyph today). One could argue that historians should use a special font that can render these two glyphs, but the problem is likely a lot more subtle than I am thinking.
As an aside: the left-hand variant is used in Japanese maps to mark the location of Buddhist temples.