Yes, the Arc will work with your TV and will connect to the TV’s HDMI ARC port. Is it worth the upgrade. Most definitely.

Will you be able to get Dolby Atmos audio? Possibly. What streaming apps do you use? Do you use any external media devices or do you use the TV’s native apps?

The Sonos Arc supports both HDMI-ARC and HDMI-eARC. 

The Atmos question has more to do with your specific TV set, and what you feed it. Since the specs you linked show HDMI-ARC, you should be able to pass Dolby Digital Plus, which is one of the ways of transmitting an Atmos signal, when it is present. Most streaming sources tend to use Dolby Digtal Plus, as it’s significantly smaller in bandwidth than MAT, which is uncompressed.

Right now, there’s not a plethora of Atmos material out there. 

You have to be the one to take the decision. I updated two Sonos PLAYBARS to the Arc, and found it to be a worthwhile upgrade. 

And depending on what devices you use to feed your TV, and their respective settings will determine whether you can get Dolby Atmos from your Arc. 

I Use Apple TV 

Apple TV provides a method by which you can choose the output (in the Audio Settings), so as long as you set it to Dolby Digital Plus, and not “Best Available”, you should be fine. However, if your new TV has eARC, then set the Apple TV to Atmos. That way, those things that are encoded in MAT will work fine, as well as any items encoded in Dolby Digital Plus. 

Only the Apple TV 4K supports Dolby Atmos audio. The older models do not. And in order to get Dolby Atmos audio from the Apple TV 4K, your TV needs to be equipped with HDMI eARC. With HDMI ARC, the Apple TV 4K is limited to Dolby Digital audio.

Your best chance to get Dolby Atmos audio from your TV is through the TV’s internal apps, specifically Netflix, Amazon Prime, or VUDU.

yes i have the latest Apple TV,

so sound like either i have to upgrade my TV or Throw away my Apple TV (until my new TV)

thank you so much guys for all your response.. appreciated!

and i placed my Order for Arc now i hv to wait

Another option is getting the HDFury Arcana eARC adapter that will allow the Apple TV to bypass your TV’s limitations and send audio directly to the Arc. I use one with my older TV and Apple TV 4K and it works great:

https://hdfury.com/product/4k-arcana-18gbps/