I saw that too, but they didn't really give any context. Is Apple saying that the iPhone DAC is insufficient? Or Macs? Or something else?

AptX Adaptive (2018+) is the only one that supports 96/24 at best, so well-shielded RCA cables from a wired DAC would probably degrade the signal less than the downmix for AptX Adaptive would, assuming your devices even support AptX Adaptive.

It's explicitly for non-Apple hardware, mainly.

They make that pretty clear. It's for audiophiles with the appropriate DAC and super high quality listening equipment, whether speakers or wired headphones.

This is what I'm excited about, too.

I work as a developer during the day, but have my home recording setup in the same room, and listen to Apple Music (or other services) all day through that.

I don't think we're in the majority, though.