The whole point of having Mathematical Alphanumeric Symbols as separate unicode code points, rather than just using normal latin characters with style markup, is so they can be used when the different letters have semantically different meanings -- in particular in maths when ๐น and ๐ can be in the same formula, representing different concepts. They're not a replacement for style markup.
In other words, they're different characters specifically so that screen readers can know to read them out loud differently!
Trying to 'fix' screenreaders by having them read anything that them as if they were normal latin characters, to accommodate people who like using the Mathematical Symbols block for fun in places which only allow plain text, would completely defeat the actual purpose of them.
