This could used to only let people hear an 8-bit (or less) "preview" if they don't pony up for the MQA decoder. In turn, this would let them distribute music where the full sound quality is only available in MQA form, which you can't edit or change in any way. I'm not sure whether there is a unique ID already in MQA files, but they could implement that, and even force software decoders to refuse to play certain files, by revoking the specific ID.
Seems like you are out of touch with the latest news to keep repeating this scare tactic/talking point. Amazon and Qobuz both publish in non-MQA high-res audio formats proving beyond any doubt that the labels have no interest whatsoever to protect their distributed content. As did outfits like HDTracks before that. Labels want money however they can get it and that is the end of the story.
Besides, MQA has no form of copy control. I can buy an MQA track, or capture a streamed version and give it to anyone I want. I can also make unlimited copies of it. So it does nothing to solve piracy problems.
And why on earth would the labels push an 8-bit format for preview when you can already get high-rate lossy MP3/AAC from major players like Apple, Amazon, Google, Spotify, etc.? You think Apple would say, "yes sir; I will go ahead and distribute 8-bit MQA and pay royalties to this little company to boot." There is no dose of reality in what you say.
The world of audio distribution has moved on and did so years and years ago from focus on piracy. Even if they did worry about it, no way, no how the labels would want to king make a company like MQA and allow them to skim money from their profits on every transaction. They would demand any such solution to be free to them. And the entire consumer electronics industry would demand the same.
Those of you who have made MQA hate your life, really need to learn how the industry works before creating these empty arguments which have already shown to be completely wrong.