"The Civil Rights Act of 1964 did not specifically limit sex to binary categorization based on biological or chromosomal sex;:"
I think that was the commonsense meaning of the word then.  
Its meaning has since been muddled with new fabricated categories.
Projecting  backwards, under the delusion that the new meanings must therefore apply in the old context, is irrational.
The meaning does not come from the word, it comes from the examples which it is used to reference.