Currently, I have not received any further updates for my two Roku Players in operation.
2016 Premiere+ - 9.0.0 build 4084
2017 Ultra - 9.0.0 build 4083
I'm still debating on upgrading the Premiere+ to a newer model. It works fine, and the minor bugs I've had with it on OS 9 aren't bad enough that I can't wait for a fix. I'm mainly considering because of the way Roku has changed the function of FandangoNOW on Walmart models, which I use so I can have the VUDU quick button. My local Walmart is out of the Ultra, and is not sure when they will get anymore, but they have the 2018 Premiere+, and a 2017 black stick. The stick I could get by with where the Premiere+ is, as it's only a 1080p setup. The reason I was waiting for the Ultra is to keep the same form factor. Either way, the need is very small at this point, so I can wait.
As far as the optical audio problem reported, has anyone been able to confirm it's a bug vs Roku disabling the port as they have removed it from all newer models of the Ultra?