I think some feather plucker at ICAO decided on the name change as there was a liklihood of some places in the distant future using exclusively ADS instead of radar to provide ATC; probably the same feather plucker who decided 'hectopascals' was a great word to use instead of 'millibars'and that if you only had a single 8.33 frequency in your FIR, then all frequencies (apart from those ending in one decimal place) must be referred to with 6 numbers.
