Wrong.
After Tenerife "Ready for take-off" was replaced by "Ready for departure". This was so that another aircraft indicating readiness could not be confused with ATC issuing a take-off clearance. The pilot readback of "Cleared..." was not dropped.
CAP 413 states:
Controllers will use the following phraseology for take off.
G-CD cleared for take-off
The quoted response is:
Cleared for take-off G-CD
JSP 552 says almost the same "c/s clear take-off; clear take-off c/s"
Both documents follow similar patterns for the Land/Roll/O'shoot clearances.
Edited to add:
TheOddOne - Sorry if I sounded a bit agresssive. I don't know if there ever was a version of CAP413 where only ATC said "cleared" with word being dropped on readback. On the occasions that I have queried this abbreviation of clearance readbacks, older folks have quoted Tenerife as the reason (and younger ones say that's what their QFI said) However, I have never seen any published phraseology (civil or mil) that agrees, which leads me to suspect that it was a myth.