Sorry if I confused anyone...so easy explanation...
MQA and ATMOS are two separate and distinct formats and they are for totally different things. So in other words, one has nothing to do with the other.
MQA is Master Quality Authenticated for stereo only (at least at the moment). MQA is also a lossy codec and requires a special, in many cases, a standalone DAC, which not all AVR's have. MQA is supposed to be the highest quality recording, taken from the master tapes, and in order to preserve DRM, Tidal uses MQA to provide a high res stereo format for streaming music.
Here is a good article to understand more about MQA: MQA audio: What is it? How can you get it?
I was confused mainly because Tidal sort of implies (or maybe I wrongly inferred) that in order to get Atmos content, I needed to set audio streaming quality to "Master."