Update and AH HA! This was apparently a Camera Raw problem. It seems (and I stress seems) that when I upgraded to the most recent release of Photoshop and Bridge, Adobe didn't update or install Camera Raw (the download and upgrade options on the CC subscription site aren't even available for some reason). So, I got on the chatbox with Adobe Support and, from what I was able to see when they had control of my computer was: Support not finding Camera Raw in my files (2) Downloading it into my files then (3) like magic, my tiff thumbnails were showing in Bridge again.
Just be clearer, the support guy did an internet search to find the Camera Raw app at Adobe. It isn't available on the front end of the Adobe CC subscription site at the time of this writing. Most curious indeed.
Anyway, thanks for sending me your thinking on this everyone, the problem was pretty serious for me for scanner vs Bridge reasons 🙂