So an update. I can still log into Zune software, but aside from seeing the account details about my subscription and which devices are authorized, there's not much I can do.
I can no longer play previously downloaded music from the computer; I'm pretty that used to play before my last post, but not anymore.
I can still not download new tracks. But now, I can no longer drag DRM music from my collection to certain (maybe all) players, and those players' tracks usage rights have expired despite syncing. So those units are useless until I load some non-DRM music.
I do have one computer and one player that are authorized. So far I can still play tracks on that one Zune device (fortunately a 64Gb HD), but I'm assuming that may go away when the tracks' licenses expire.
Groove still works, and I guess I'll have to adopt the Groove app for my iPhone for mobile listening. I'm not sure I can download tracks to this mobile device for offline listening like I can for my computer.
I assume this isn't going to change, so now I have a subscription until February 2018 that is seriously compromised. No more 120Gb, 30Gb, and 16Gb Zunes loaded with listenable DRM tunes. And I'm assuming my 64Gb will go away, too.
If anyone else is still alive and "listening" in this Zune wasteland, let me know. I'm out of tricks.