Upgrade 7.1 to Atmos, can the tv decode it for me and send the signal via ARC

It's time to upgrade my TV.  Looking at an LG65 inch OLED with Atmos.
My pre/pro is DD 7.1 but does have ARC to get audio from the TV.
Can I stream via wifi to my tv and have it send the Atmos signal to my Emotiva UMC-200.  Will that allow me to run Atmos sound with 7.1 sound?  The TV's should have Atmos decoding.
The budget isn't there to upgrade the TV and pre/pro right now.
Rest of theater is Mac amps and Coincident speakers all around with an Oppo 105. 

I don’t think you’ll have any problem playing new tracks with your DD decoder.

It won’t exactly "decode Atmos" but you will get the 5.1 in the stream.

You may have to configure the TV to tell it what kind of output it can take. Not sure how automated this is via HDMI/ARC. Using optical I absolutely have to tell it whether my DAC is 2 or 5.1 capable.

I find the ARC handshaking somewhat iffy at times, if you do as well, switch to the optical out.

Thanks Eric,
I love my current 7.1 and just wanted to add Atmos without buying a new pre.  It looks like I may end up buying an OLED TV without Atmos and then start searching for a pre later.
Short answer.........maybe if the TV has the required outputs and atmos processing capability and you have a more than 7ch amplifier. In other words direct to amplifier connection. The Emotiva UMC 200 is not capable of supporting Atmos encoding. The best it can do is 5.1 and 7.1. True Atmos can support up to 32 seperate/discrete amplified channels. I believe the highest number so far is 20 but I may be wrong.
So with your proposed configuration the answer is no you cannot get "true atmos" you can add speakers but that will not get you atmos only 7.1 at best with more speakers playing the same signal.

Hope this clarifies.
My new TV comes Wednesday 65" E class LG OLED.
For the first time ever my video might be better than my audio.  More to come...