In addition to autofocus improvements, the rumored Nikon Z6/Z7 firmware update that is expected next week could also add compatibility for other CFExpress memory card brands (the last update added support only for Sony CFExpress cards).
Here is an updated list of CFExpress companies:
In the US, CFexpress cards are sold at Adorama, B&H, and Amazon.
The first price drop on Sony CFexpress Type B TOUGH memory cards in the US: Adorama | B&H | Amazon.
In Europe, CFexpress cards can be found at Amazon UK, Amazon France, Amazon Italy, and Amazon Spain.