Nikon removed mention of the new Auto Capture feature coming to the Z8 from their YouTube video about the Z9 firmware update 4.0:
In the above video, it was clearly stated that the Auto Capture function will also be coming to the Nikon Z8 soon (around the 1:42 mark). That remark was later removed, but many readers already saw it in the video.
Nikon also removed the related portion from their Z8 press release:
“Upcoming features will be added in planned firmware updates, including an Auto Capture function, which will allow a photographer to automatically trigger a remote camera on user-set parameters. An update will also allow for the base ISO to be extended down to 200 when shooting video footage with N-Log enabled.”
I think Nikon realized that the new Z8 is too good of a camera and in a way makes the Z9 obsolete. They wanted to create a mini Z9 and now they are removing features from the Z8. I hope I am wrong in my interpretation.