I’m surprised.. but not really.. that the Sonos reps that come here with their announcements don’t answer this as I’m sure they would know  the correct response. 

Yes, this is about speakers firmware update, not the controller app.
Unlike controller app (on Android at least), you won’t be able to downgrade the firmware if the newer version doesn’t work well.
IMO now the safest option is to stay with the old 16.1 both speaker firmware and mobile app - if this configuration works well for you.
That’s what I have now and I think I won’t update anything in the nearest weeks or months until Sonos cleans up their current software mess.

There was a useful post from a Sonos person yesterday highlighting different combinations of the FW and controller app versions and possible issues - take a look.
 

I unfortunately had the new app install itself on my iPad but I’ve kept the old apps on my Android phones. This morning I updated the iPad and immediately got that message. I assumed it would do a speaker update so I’ve removed Sonos completely from my iPad because the new app is unfit for purpose for my needs.

Hopefully I will be able to keep running the old app on my Android devices.

Thanks all, I think the consensus so far is that it’s best to keep one’s head down and ignore all the update messages until a fair bit of the dust settles.

I am very glad that my Controllers are Android based.  I was with a friend yesterday who is on Apple and he is absolutely incandescent about what the downdate has done to him with no rollback in sight.

Michael.B - I had a look at the link you kindly posted.  What I found interesting was that while Mike R H  was very specific about the various firmware Versions he never once mentioned a Controller software Version. 

Could it possibly be that they’ve lost track of them already?

Just a thought….

Here’s some info that might help you sort out where you are.  If you, like me, naively updated your components firmware and app before finding out what a nightmare that becomes, you may be stuck in a “compatibility scenario”.  But even this announcement seems inaccurate and geared toward steering unwitting customers into the abyss.

I’m stuck in a “compatibility scenario”: hardware updated, iPhone updated, iPad old working app, SonoPhone 3rd party working app, Desktop working app.  The only thing I need the new broken app for in this scenario is for system configuration (adding devices, pairing speakers, etc.) and I’m certainly not adding anything new and my systems is configured.

My “compatibility scenario” could be summed in that my music system goals are incompatible with Sonos’ sales goals.  I don’t want their headphones or their music streaming service or anything much else to do with them.

Here’s a post with the “Sonos party line” describing “compatibility scenarios”.  It’s probably mostly correct, but the bits that aren’t correct make the entire thing worrisome - that and the “herding sheep” tone.

I got the same message and was hoping it would help.  It did not in my case.  If my sub is unplugged, the system seems happy.  If my sub is plugged up, the system looses it’s mind.  Hope Sonos can figure it out soon.

I think Sonos are being really underhand with this.

They seem to be pushing controller app updates which I’m ignoring on iOS as if you update to the latest iOS controller app, you get this (as per my work iPhone): -

My personal i-devices are all on the first version of the 80.x controller “upgrade” and I can still manage my Sonos devices that I’ve left on firmware version 16.1.1.  I have no intention of running the system updates as I’ll be locked out of using the older controller apps.

Thankfully I have an Android device that I use as a DAP while travelling so have been able to roll back to an older version of the controller app and still have access to alarms and sleep timer settings.

Sonos - this is disgraceful behaviour.

If your NAS doesn't have SMBV2/3 but only SMBV1, then the firmware update will remove access to your files on the NAS. Be warned!