I decided to double-down and get the full CMC series before they’re gone, completely. The fader units are still available from some sellers in Japan, for some reason.
They’re great little units.
I have faith they’re going to be supported and if not, there’s always Bome MIDI Translator Pro.
I’ve confirmed that they show up and transmit messages that can be manipulated by Bome MT. So going out of the CMCs is straightforward.
As for getting back in the CMCs (for bidirectional feedback), reverse engineering the messages they respond to might be trickier, but not impossible.
Worst case scenario, I’ve got a rack of PCs, so even if the drivers are not supported in some future OS version, or even in Cubase itself, I’ll be able to dedicated a cheap 1U rack build to Win 7 and re-route the MIDI messages out physical MIDI cables to Cubase where they could be mapped via a Generic Remote (a reason to hang on to those old Win 7 licenses before they’re all gone – as Microsoft doesn’t sell Win 7 anymore).
No promises, but if Steinberg drops support and I end up creating some useful Bome MT patches, I’ll be sure to share them here – unless Steinberg drops this forum, altogether. 
Folks, we’re living in a modern dystopia were technology somehow gets uninvented. Stuff we used to have, that was good, goes away.