New Playbar Release Any Indication ?

I am only concern is HDMi ARC will offer a better sound quality as compared to current optical connectivity.
Digital is digital. Whether the bits travel over HDMI or optical is irrelevant. The audio quality in digital audio is affected by the resolution (i.e. 16 or 24 bit) and sample rate (i.e. 44, 48, 96, 192 KHz), as well as any compression that may be applied to the audio (i.e. MP3, AAC, etc.). And yes, Dolby Digital is considered to be a compressed format, as it runs as high as 640 Kbps for 5.1 audio (source), compared to uncompressed PCM stereo (2.0) audio that uses about 1.4 Mbps.

I think the next Playbar refresh will need to support 7.1 if Sonos plans to stay in the home theater game. 24-bit audio support might need to come with that, as I know DTS uses 24/96 audio (which is likely why it wasn't included in the current Playbar), and I would expect that Dolby's 7.1 encoding probably does as well, though I have nothing to confirm that yet (I think DD+ and TrueHD, which support 7.1, are likely still 16/48, but I would be surprised if Atmos wasn't 24-bit).

Looks good.

http://www.theverge.com/circuitbreaker/2017/2/21/14682242/leaked-sonos-playbase-is-a-soundbar-that-your-tv-sits-on

Well I to love Sonos but I think sometimes my vision is too narrow on when it comes to what I am using it for. .. I am not terribly big on rumors or speculations when the market if full of possible alternatives. .Sound bars are different now then what they were when teh playbar came out. For me I think Sonos is resting on past lorals and fans. Don't get me wrong I love their stuff dispite the price increase which is because i live in Canada and the exchange sucks. But I also don't like all the things that I must do to make things work..example buy a new switch because my Tv doesn't pass the audio right. So the playbar came out in Feb 2013 fast forward 4 years and now we are seeing soundsbars with Atmos built in. (I know there's not much if any content but my point is at a cheaper price point I get some pretty rich features) Sonos to me is like Apple...they really are relying on the fans to remain loyal. Really all the play bar is for me is a way of cleaning up all the audio gear I had in my living room so that my room is tidier. By the way that cost was almost 1800 dollars (Now over 2300 with taxes) to do and has so many limitations that sometimes I think I must have been crazy. . Sonos can never replace my home theater gear. ..sorry to say doesn't come close to sound when watching movies.
The new play 5 what did it do.... it does sound better than the old play 5 but really plays nothing more. I would have thought about it if it had of had some other innovation such as siri integration or I guess for people in the US google home or Alexia. Don't get me wrong I am all for better sound but that better sound has to be subtancial. I mean the price increase for me was 200 bucks in canada. I lost the portal handle for carrying out to my back deck and I lost the headphone jack...hmmmm and I pay more...my (old)play 5 is a bedroom speaker and it's still awesome.

So now I will look at possibly something else because sonos is is slow to deal with what is in the modern world. Does it mean I will abandon sonos...likely not ..What it does mean is I may look for a more advance (feature rich) sound bar and then connect a Sonos Connect. If MY soundbar has auto sensing then it should still be able to play my sonos when needed...as in like by alarms I have setup.
Now you may see why I think my vision is tooooo narrowly focused on Sonos for my entertaiment system in my living room.

Some times we need to reevaluate why we bought something and what has changed since that time in the market.....you just may make some new discoveries.
I made a discovery....as I age I have discovered my hearing is not as good as when I was young...that's life or should I say biology i guess....LOL