Years ago introduced technology on a one off basis. For example eye control went no where,
Eye Control was on the A2E (5), 50e, 30e and 30v, and the 3, and one of the APS EOS cameras (as in APS film) It was sold on cameras between 1992-2007 (the latest the EOS 3 was listed as a current model by canon, the most recent new model to feature ECF was the 30v, launched in 2004) so it was far from a one off basis.
Widely revered, widely derided. It's hard to think of a more devisive feature amongst Canon users of a certain generation. I loved it and wish they would bring it back. It had an off switch. I never use spot average flash metering, but I don't get upset by cameras having it.
Point was not to deride eye control, but to point out that starts with technology which it tests in the marketplace. They seem to stopped that process in the last 5 yrs and I wonder if they will make intrude the foreon sensor too early?