If a symbol is part of the Nemeth Code it does not have to listed on the Special Symbols page. Be aware, however, that Computer Code symbols, Chemistry symbols and some literary braille symbols have to be listed.
I don't believe the guidelines direct that Nemeth rules should be altered. When the updated guidelines are completed there may be more detailed instructions about this. Currently, Nemeth Code symbols are not required to be listed on the Special Symbols page, even of K-3 materials. I don't intend to give any advice about this, except use your own best judgment.