That's how it appears - but then I've seen things suggesting Big Sur supports it, and the option is there to turn it on. But then it talks about speakers or headphones that support it. But - whether it's sending it to speakers or headphones, it should be sending the atmos signal.
Problem is, whoever I get at support isn't going to have a damn clue about any of this! Ask anyone at tidal or amazon about getting atmos onto a marantz receiver, and their canned response is, oh, we don't support marantz hardware at this time. Yet.....it works perfectly fine once configured properly. Until it doesn't, of course. No one has a fucking clue what they're doing, and when things get to the point that I barely have a clue, then things have gone off the fucking rails! Dolby needs to get their collective heads out of their asses, and fucking fix this shit!