Not possible.

The Unicode Consortium will no longer accept proposals for flags.

https://unicode.org/emoji/proposals.html#Region_Flags_Withou...

Actually, they can do it by adding a new ISO 3166-1 alpha-2 country code. By splitting a country or merging several.

there 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.

[dead]