You can disable automatic player updates. You should also disable automatic updates on your controller devices.

You only joined the forums today, yet you moan about some speakers not working whilst others need updating. From this I have to conclude you have multiple rooms and speakers that you’ve added to over time.
So how come you’ve not encountered this issue before? Or that you’re only now complaining about it in such an uncompromising way? 
Or, if you’re installing a new system, why are you so outraged that all speakers need to be on a compatible version (which generally only takes a few minutes anyway)? 

​@FireEveryone 

Your screenshot imho shows the result of an automatic or manual app update. 
So now your devices firmware also has to be updated. 

The pop up dialog is shown every time I open the app, I can’t access anything else as a result of this dialog. I have 3 devices in my house - 1 arc, 2 Sonos sl speakers, the two speakers aren’t updating no matter how many times I’ve tried

the update fails every time, I’ve tried restarting the speakers too. 

I can’t even access this on the app, the dialog to update takes over as soon as I open it

If you’ve restarted the speakers, you may want to restart the router too. And check for any port blocking software, such as VPNs, work profiles, or even virus protection software. 

Finally, if none of that makes a difference, I would call Sonos Support directly to discuss it.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

I think there’s 2 possibility here:

1. Update fails because device can’t connect to internet, if so, why is it necessary to require the device which supposedly can’t connect to the internet to update?
2. Update fails for some other reason but device is still accessible in network

In either case, I still don’t understand how this behavior can be considered correct

Because your Sonos app has updated, but your speakers haven’t (or vice versa)? There needs to be a match between the two. I’m curious, what did support say when you called in? 

I hard-wired one of the speakers to my router to fix this issue.

And have you turned off AutoUpdate to stop the risk of it happening again? 

You have no idea what you’re talking about - automatic update was disabled. Stop making assumptions.

Moderator Note: Modified in accordance with the Community Code of Conduct.

It was a suggestion from ​@buzz several days ago, which had gleaned no response from you. If it wasn’t disabled, the situation may have arisen again. I made no assumptions whatsoever; I simply asked the question which, albeit quite rudely, you have now answered. Despite your rudeness, I hope you now continue to enjoy your system.