You should see this message: "There's a problem with the [your device name] that requires it to be updated or restored." This message is not happening.

I don't know which step worked, but I did all these:

1. Removed smart battery case
2. Used new USB C - Lightning connector from Apple
3. Plugged that cable into a port on the MBP instead of through multimedia adapter
4. Suddenly iPhone device popped up on Finder with pop up message "cannot restore - not connected to Internet"
5. Was using dedicated cable, but I enabled wi-fi going out thru ATT gigabit fiber
6. Choice to update / restore popped up - chose update per original instructions

I think I'm out of the woods on this. Not sure why the original message did not pop, but I could see that my iPhone did not show up as connected on a USB Hub when on the system report - that seemed to be the key issue

That's the link I am already looking at that says I'll see the message "There's a problem with the [your device name] that requires it to be updated or restored." But I don't see the message and don't have a link to click "Update"

Thanks lobsterghost1. I did go looking for other links inspired by your point, and did see one about looking for your iPhone in the system report. Looks like that was the trick. If it's not there, you don't get the message. Kindest regards and stay healthy in the months ahead.

PS - iPhone shows up on USB 3.1 Bus