I think I found the answer. It seems the displayed message is coming from an application that the firmware process puts in the Wio and is running. So the message will persist until a new upload is done to the device. Or so it seems.
Here’s what I did:
(1) I couldn’t get another application to upload right away, not sure if there was something about reset or power down sequencing etc. But at some point I could get another app to upload into the wio.
(2) once I uploaded a new app, no problem. It worked and the wio is up and running. No more firmware message.
The wiki doc really needs to spell this out. It’s not obvious and it caught me by surprise. I succeeded in updating RTL firmware and can run Wi-Fi applications without a problem.