That is a good question. The M22s are nice for sure, but too much for surrounds? Possibly.
Too much for Atmos? Maybe, but maybe not. The Atmos spec states that ALL speakers should be "full range" speakers, not just your front left/center/right. That doesn't mean M60s for the "surrounds" but that the speaker needs to be able to effortlessly get a little "deeper" than some small speakers. The M22s can go about 10Hz lower than the M2 for example, but the M2 is no slouch. Since people have subwoofers in their rooms (or should, and you know who you are out there that don't), the M2 should do just fine as "surround" speakers and overhead speakers for Atmos.
So while I personally think that the M2 lineup would work well for an Atmos setup, I don't want to discount anyone wanting to spend a few extra bucks on M22s thinking that there wouldn't be any benefit. I just don't think that there would be enough benefit for the cost.
