At last the change has filtered through to the college! I had more or less given up on telling ADC u/t's that the "readback" bit wasn't necessary, but it was too ingrained. As 166k says, it would be crazy to use it elsewhere, especially in area control. However, it has been the convention for decades to use it in response to airways clearance readbacks, in the UK anyway.
Another anomaly is "Report final" for the first aircraft in a visual sequence. When it was decreed that the "number one" bit should be dropped, pilots immediately started asking "Are we Number one?" Far too woolly, and in my experience controllers rapidly reinstated it and do so to this day. Is it still in CAP413, I can't be bothered to check?