Interesting indeed !
Never got any discount either on my AFKL gold in the past 15 years despite billing 50-70k/ y on it. I wasn’t even aware they had this policy.
As for the platinum one, every time an agent tried to upsell me I said I would consider it if the first year was discounted. They never accepted.
These days the silver Amex looks more and more appealing... way to retain customers !