...and finally, never mind again. We're up.
If anybody else runs into this, here's what I think happened.
Following the update, we needed to manually sync the Application Group Licensing from the Network Elements form. Certainly on the one that was misbehaving, maybe from the DLM as well.
We didn't figure that out, and on the advice of our VAR, deactivated and re-activated Service Link from the Server-Manager interface. I believe this is what wiped out our GARID.
We got our GARID from our VAR, re-entered it on the DLM.
First from the DLM, and then from the non-DLM cluster member, we sync'd the Application Group Licensing from the Network Elements form.
Then, in the same order, we went to the Server-Manger for both, and did an AML/Service Link sync for both elements.
Last, we re-did the manual sync of the Application Group Licensing from the Network Elements form.
Licensing is all straightened out, and no alarms. I suspect those last 3 steps (6 steps, really) were more than what was absolutely necessary, but it worked for me.