Sonos Connect is second generation.  If any Sonos devices are going to be bricked, they will start with the first generation ZP80 and ZP100 before the Connect.  So I’d hold off on the panic button until you see those announced not being supported anymore.  

The discontinuation is announced for Connect; Connect:Amp and 1st Play 5:
https://gizmodo.com/sonos-is-officially-killing-off-some-of-its-older-speak-1841069879

Will the Port be generally available for tradeup of the Connects?

Only older Connect devices are affected. You can check this here: https://www.sonos.com/myaccount/system/households/devices/ 

If you opt for trade in any Sonos device will be elligible for the discount. 

But the replacement for the Connect does not have optical out so completely useless to me and I suspect many others.

Absolute ****. To say if your using a connect amp that the rest of your setup won't get updates is pure blackmail. I have spent Thousands on my sonos system throughout the house and I have a connect and a connect amp, what a disgrace sonos.

Message to Sonos

Are there any internal hardware/performance differences whatsoever between Legacy ZP90 and a non legacy Connect?

Can a connect really do anything that a ZP90 connect can’t?

I’m a fuming brand ambassador for you with 8 devices with now 7 unsupported whose just been shafted by those who should be showing gratitude rather than this…

Oh, and will any new products connect software downgrade to a legacy system?

I just got the e-mail telling me that my Connect and Bridge (not sure I still need that tbh as I think they changed how their wireless works) are legacy and won't receive any updates after May. How much of an issue this is will presumably depend on whether I can still access the functionality I need across the rest of my Sonos kit without the software upgrades.

Given how over priced the Connect was in the first place I can't say I am massively enthused about the prospect of "upgrading" to the even more expensive Port (which is missing the optical out of the Connect as far as I can tell).

Really disappointing tbh and I am now glad I didn’t pick up a number of additional speakers over Christmas when all the offers were on.

For something dubbed “Sonos Port”, it surely doesn’t have very many.

Just received the same email that my Bridge (which I’m not concerned over) and my Connect (which I am VERY VERY CONCERNED about) are being deprecated. I’ve been hoping for a successor to the Connect for a number of years now but the new Port is most certainly not what I was hoping for and in fact (as mentioned here) REMOVES features I use and require.

My Sonos experience, once a shining example of what is possible in 21st century audio, has been slowing turning into a bit of a shiteshow over the past 3 or so years. 
The Port is rendered even more “niche” which is a shame - simply adding connectivity options that crossover from other products, for instance adding HDMI and/or optical *INPUT* to the Port whilst retaining the i/o it already has would have been incredibly welcomed. This is already present in AMP and I’m at a loss as to why PORT was designed this way without. I’m at a loss over all of this in general.
 

A coax to optical adapter can be had for < $20.

...which adds 3 additional cables to manage, an additional power requirement, and the peace-of-mind that goes with adding a <$20 off-brand device to the signal chain.

Just listing the option.  You don’t have to use it (or even care, considering I gave it to someone else and not you).  

It’s accurate. Just listing the negatives, as I came to join the conversation, which is pertinent to my use environment.

But shouldn’t have to buy an adapter and cannot believe that using an adapter doesn’t degrade the audio quality.

I gave no comment on what should or shouldn’t be.  I merely gave a option.