Would agree, BOAC, and indeed thus is indicated on additional Jep pages in the LHR section....for the FIRST call only.
But it says nothing about descending aircraft reporting passing altitudes, nor does it address climbing aircraft once they have left the standard instrument departure (DP in the USA), so I would maintain that mentioning passing altitudes/flight levels is otherwise not required (unless specifically requested to do so) and further, adds to frequency congestion.