Basically whenever Sonos choose to do so. It has removed the justification in my case to collect their devices over the years and stopped my planned Sonos purchases. I was such a fan until this despite the slow feature development!

Sonos provides updates and full support for five years after a device is no longer sold. The Play 5 Gen 2 is still being sold so no minimum date can be given.

Keep in mind too, this is a minimum Sonos fully supported and updated my ZP-80 for many more than the minimum five years.

Also all devices not on the Legacy list today have far more internal resources than the gear that was listed so the need for Sonos to go through this painful process again is much reduced.

It only has 256 MB of Ram. IMO it's a no buy because when Sonos rolls out their local voice control (snips) increases local index and adds amazing new features 256 isn't going to be enough. 

256 MB is 8 times as much as the 32 in the devices being moved to legacy so there is a lot of free space to give us a cushion.

I’m happy with the 14 year run my ZPs had, and they would still be working (just not getting updates) id I hadn’t traded them and scrapped my old AVR gear.

I find amazing that in this day and age, when everyone is trying to lower our ecological footprint, an enterprise like Sonos, known for it’s advance research in technology,  is basically telling us that our systems will soon be good enough for the landfill. If the reason is the lack of memory, what about planning for a plug-in external memory. Pretty sure it could be done. If the problem, as I was told. is that Spotify wil not be able to connect at one point pass May 2020, what about proposing a tool that will be used in the local plug-in that connects to the back of our systems. But NO, Sonos wants to sell us more stuff and is asking us to throw our divices in the garbage.

Such a disappointment Sonos. Good thing I stopped at three divices. My buddy has his whole house plugged in to Sonos…

Jules