Depends on whether you feel the need to upgrade to S2, which you may not, and that’s fine. The BRIDGE should be removed from your system in any case, they’re known to have issues with their power supplies, which can end up causing some fairly random and hard to trace symptoms. You can choose to upgrade it to the much more recent BOOST, or you could just wire one of your speakers to your router, or, you could just connect your system to your WiFi signal. 

The BRIDGE is definitely not S2 capable, your CONNECT may, or may not be. You can log in here to check the status of your devices.

The successor to the BRIDGE is indeed the BOOST, and as you’ve identified, the successor to the CONNECT is indeed the Port, but it does have slightly different outputs, so you should double check it has what you need before you take the decision.

Thanks!

I do not see benefit to you from upgrading if that is all you use Sonos for; there will be no change in the listening experience. And your existing Sonos kit probably has years of life left in it.