Good. The complaint letters are working. Though until we actually see what the "changes" will be it's all just words. If you haven't voiced your opposition yet (and you'd like to) then you should. Email CS and be polite of course...

Obviously, if the # of Diamonds "doubled after. Covid" then maybe it's the 3-year rollovers. You could have 20 Diamonds on a flight or 10, if there are no seats in F available then no one's getting an upgrade. The number one reason why upgrades are harder to come by is dollar spend is making people buy it more. Increasing requirements to $35K is not going to change that and may make more people buy F.