I think we got the Biz Gold around the same time last year (AF glitch time?) since my AF just posted too. I'm trying to decide if I'm going to hold onto mine to sign DH up for something through my card, for the 25K support (with the Schwab Plat that's worth $312 to me so the AF would be offset). He's already had the Biz Plat, BGR, and Biz Green (all 3 have been canceled in the past 12 months), and also has the BBP (which I think is a great call for your DH!). I've been contemplating the Plum for him for a while, but I'm also wanting a $0 AF card to hold on to keep Amex happy since I'm probably canceling his Bonvoy Biz and Hilton Biz this year. I might do the Blue Biz Cash for him just because of the $0AF. The SUB (via incognito, $250 on $10K MSR) on that is paltry so I may not even bother trying to hit MSR on it. I realize the Plum is $0AF for the first year, but since I'm anticipating closing his Bonvoy and Hilton cards, and his account has 3 other cards closed in the last year, I don't really want to poke the bear (RAT) by closing the Plum in a year. I'm running out of Amex cards that interest me.
Have you experienced the pop ups? I can say that neither DH or I have gotten a pop up, and we have both canceled Amex cards a couple months prior to being approved for other Amex cards. That said, we have a long history with Amex (17 years) so that may play a part in it too. And we put a lot of grocery spend on our Golds.
I agree with your thinking about deciding on your Plat retention offer before canceling your Biz Gold. I would think about if you can use those 4x categories on the Biz Gold, and the 25% points rebate for flights on your chosen airline, and weigh if those benefits help you out at all. In the past year I've been paying attention, the Biz Gold has had the highest support links of all the MR cards FWIW.