MPN11, my post was meant to be tongue in cheek hence VSO(desk). I just think that's probably the line of thinking that led to the change. IMHO the similar names are confusing rather than helpful.
It wasn't seen necessary to rename Navs (or Observers) RIOs or CSOs during the F4's UK service life. I am of the 'If it ain't broke don't fix it' school.
I can't see why the RN saw the need to change Tiffys (Artificers) in Engineering Technicians or why Jimmys slowly changed from Number 1 to XO (though the latter was probably just organic cultural change driven by USN dominance in NATO and the love of acronyms).