If past is prologue, there’s going to be a sizable increase in the upfront annual fee with some sort of benefit/credit that if has 100% utilization brings the actual fee way down. I’m skeptical about Prime as that would have minimal breakage opportunities.
It seems to me that Amex wants to drive customers into a single product for the vast majority of their spend, with Gold being the sweet spot for most customers.
If customers really do want multipliers on a large number of categories, Amex will not cede space to competitors, but it will cost customers, probably upwards of $1,000 in annual fees for Green, Gold, and Platinum.