Purwacarita, you seem to have a somewhat reversed way of looking at this, but in the end, perhaps we both have a similar understanding.
The Yoni IS a repesentation of the genitalia (sex organ) which obviously symbolized energies that are greater than the organ itself. The symbol is not used in "sex/genitals" as you suggest.
That is to say that the "map" should not be confused for the "territory". Yoni has had a particular meaning for a very long time. To suddenly change that meaning can be very confusing for proper understanding. Yoni is a symbol, and therefore the "map", or at least a character on the map. You seem to be using the word to embody the thing itself. For me it does not work.