Renewed my Amb yesterday and did not have my Diamond extended to the end of 2024. Honestly, IHG Diamond just isn't as good as say Marriott Platinum since tons of IHG benefits are separated into their Milestone rewards. Plus, the main differentiator between IHG Plat and Diamond are the free breakfast and more points on paid stays. Upgrades have just been 1 category up most of the time.

I still find Amb worth renewing despite the trick being dead since they tend to have renewal offers, and it's quite easy to get 0.8-1cpp redemptions with IHG points. Guaranteed 4pm checkout at IC's is nice too. Still a useful program for those stays where I don't really care for the free breakfast since IHG points value have gone up thanks to the 4th night free benefit from IHG credit cards.