Does the system play through the TV speakers without the Sonos connected? Then yes it should.

The PLAYBAR has no idea where the content is coming from, so anything your TV plays via HDMI should be output via the optical port (or, in the case of ARC or eARC devices, through that port). The TV itself knows where the content is from, but that isn’t ever passed to the Sonos. Only the audio. 

I don’t recommend attempting to do Karaoke using a SONOS soundbar. There is a slight audio latency that will frustrate most singers,

However, if that audio is being delivered to the TV set via HDMI, and then the digital signal sent to the Sonos, you won’t have that perceptible delay. 

I read that in some other posts but the ones saying that were going through an amp.  In order to do that they must have 100% pass through on the amp.  Thank you for your response and any other helpful info you have I’d sure use it. 

There is no pass through on a Sonos Amp, without a delay. You can use the lower latency HDMI-ARC input (essentially from a TV), or the analog input which is high latency (around75 ms)

Essentially, if you’re not carrying the audio on HDMI ARC or the digital optical input on some Sonos devices, Sonos is a bad system for Karaoke.