I think the intended point was that, since there were only 3 votes at a website devoted to multichannel releases, that it is obvious that they priced this box set so high that it dissuaded the very people that would care about such a mix from buying it. (Much like is going to happen with the Moving Pictures box.)I don't think you will ever see this in the bargain bins. I bet this sold just fine, as there are MANY MANY die-hard Kiss junkies out there that would swoop this box up, even at the list price, for all the swag within. And probably 99% of them have neither the setup nor the interest in the Atmos mix.
That being said, there are user reviews of the Atmos mix out there, both within this thread and over at the Steve Hoffman site, you will just have to dig for them. Or, of course, you can listen for yourself on Apple Music.
I agree with you that it will probably never appear in the bargain bins, but with Kiss' history of never leaving any money on the table, it would not surprise me if they eventually release it as a stand-alone bluray or maybe just music only package without all the swag. I am not holding my breath though.