Personally I usually use 'AG' as an abbreviation for 'Androgyne' or simply 'Androgyne', but of course I also use 'Andro'.
I think it has to do with the context/situation where it is used.
As someone else pointed out; forum looseness.
I'd like to top that with; the forum Susans. On this forum, in this situation/context, the word 'andro' is a reference to 'Androgyne' without question since that is how the forum context is lay-out.
Communities, forums tend to have their own lingo. Thus, in this specific situation, it is actually correct...
However, yes, in the 'outside world' terms used here can/do have different meanings, but I like to think it would actually be quite easy to give the word 'andro' a double definition in the outside world due to the lack of knowledge of 'Androgyne' as a whole..
Just some early coffee thoughts from my side.