Sorry mate, but I didn't explain myself properly. I agree totally with what you say about keeping the cruisers on through to the sixties.
What I was trying to point out that when most of them were built between 1945 and 1949, there were no known gun-armed naval opponents around worthy of their steel.
The US must have got the message because I recall that about 10 of the 10,000 ton CLs building in 1946 were converted to CVLs whilst still on the slips.