Sonos Announcement today 1/21/2020

I just took a very brief glance at that thread: wow! 
I guess the BIG question is: will having legacy gear in the same chain as newer Sonos gear kill your ability to get Sonos updates (which are vital to the system working)...

From CNBC:

“Sonos said people who own the older products can keep using the older speaker in their system, but the new speakers won't receive updates either. A spokesperson told CNBC this is because all speakers on run on the same software, so an older one will lag the system behind if it's still in use.

Sonos told CNBC in May it will launch a way for customers to segment the older products into a separate speaker group, which won't receive updates, while another group of newer products will continue to get new software.”

My Android phone no longer is fully compatible as of 6 months ago. So while most companies work on improvements as Sonos should so they could be more compatible with HiRes, they have been working on obsolescence!

I think I have figured out the acronym for Sonos

So
Old
Now
Outdated
Sucker

What will happen is as soon as your music service makes a change and Sonos changes their software to stay in sync your done.  You can proly keep them around for streaming radio.