No. The Arc requires the eARC signal (or just an ARC signal) to work. If you hook it up to the other ports, there shouldn’t be anything traveling from the TV to the Arc. 

it sucks

any reliable hdmi 2.1 splitters available

thanks in advance 

they should make all ports arc workable 

just a thought

Sonos doesn’t make TVs. They have no control over what manufacturers choose to make an eARC port, but I certainly support the concept that all of them should be. 

You can search on Amazon for HDMI splitter/switches, and find quite a few capable devices, I suspect. 

There is no need to have more than one ARC or eARC port on a TV. The idea of ARC or eARC is to allow the TV to send audio from TV Apps or connected devices back to a receiver or the SONOS ARC. If you need two HDMI 2.1 ports this a different issue. 

Here is a discussion about HDMI 2.1.

I would argue the value of not having the consumer need to be aware that one HDMI port is different than any other might offset the slight cost of the electronics of allowing each port to be ARC. But as you say, there is no reason I can think of in which you should use more than one ARC port. But certainly any device supplying a signal can be plugged in to any HDMI port. Only a speaker that connects via HDMI ARC needs to connect to that single labeled port. For input, they’re all the same. 

If they (Sony) could put second arc port ,that would be nice ,in this instance I got limited choices ,2 HDMI 2.1 devices plus earc soundbar , with just two newest port's available when I need three,I bet There is more people like me 

Screw you Sony.

Thanks Sonos for your stuff- p.s. Hopefully you can rectify lpcm issues

good article , thanks