Is there something new in this CDA thingy then?
Circa 30 years ago it was a matter of professional pride to close the thrust levers at top of descent (F330 or more) and not be spooling up until 3 or 4 miles from touchdown - and, by the way, this was hand flown with distance to touchdown being mentally calculated using VOR/DME (barrel type) and/or ADF.
With all the gizmos available now people seem to make such a song and a dance about it - KISS!