That's the question everyone asks when they get this pop up, right?
I don't know. I thought I was doing a pretty good job keeping up spend on my wife's cards. We've been meeting MSR on her Hilton Biz, so that's seen a lot of action recently. And I've been using her SPG Biz for gas, and linked it to RMN for a few hundred worth in GCs last month. There was about 2 months after MSR when we had sockdrawered the SPG Biz (before we knew about the pop ups), but that didn't stop my wife from getting approved for the Hilton Biz during that time; and we've put about $1.5k in spend on the SPG Biz in the last 3 months.
I guess this is a sign to keep using the Amex cards DW already has and take it slow. She's still 2/24 with Chase, so maybe we'll try for the CIC for her in a few months. Meanwhile, I'll try for the Amex Gold periodically once we have a better idea what the offers are like. DW has until January to get her own Rose Gold metal card.