Edouard, thanks.
I am just replying because I was at the location this weekend and trying to install it there.
It appears that I am unstuck and it is working. I am not totally sure what did the trick, but there are a few peculiarities of this system that may have contributed. I downloaded a fresh version of the driver, which had been updated and installed it, rebooted both computer and console while connected. At some point it clicked, but see below.
The peculiarity here is that this MBP is in a weekend/vacation mountain home. We often let friends and family use it and it had been set up with a guest user account for them to use. We had had a problem on the old MBP of it rebooting and WC not starting up. Since no one was there, we were not sure of the cause, or aware of when it happened. On the replacement, I had the Genius Bar try to set up the computer to auto reboot with WC in the startup list in the root. However, the way they set up the user accounts, the guest account was the one that was booted to first. WC was set up to be available to all users, so, while I logged in in my account to install the drivers and had the WC data files, etc., located there, I was unaware that a version of WC had already started connected to the guest account, but had no access to the WC setup preferences, data and support files in my user account, and so I think it did not do a full startup and stalled in initialization. I think that this must have created a conflict as the version in my account tried to access the same input port and console as the stalled WC, so the "data not ready" message came up in my account. I am not an IT expert, so this may be off, but it makes sense.
I eventually installed Lingon and set up a root job that referenced the WC app in MY user directories to start on boot and it seems to work. BTW, I am using a direct mini-USB to USB-C cable with no intervening Apple adapter dongle. Not sure if that makes a difference or not.
We will see how well or long this works remotely and unmonitored.