That's a big—and new—step for Apple, and I'm sure it's connected to the video service. They don't want it to be "Apple product exclusive," even if I'm sure they'd rather you use Apple products to watch it.
But Apple hasn't ever been quite as exclusive as they're painted to be when it comes to peripherals and services. They've had iTunes on Windows for a very long time (yes, it's kind of a trash fire, but it's still there), and that was mostly to support the iPod. They have iCloud for Windows. Apple Music has an Android app, is supported by Sonos and Amazon Alexa, and even has a web-based API (no official "cloud player," but there's an open source one out there which Apple knows about and is apparently okay with as long as it doesn't use the word "Apple" in its name). And, of course, a lot of non-Apple products can receive AirPlay, and they appear to have gotten fairly aggressive in the last few months at moving AirPlay 2 into the third-party market.
So, Apple Services have been on third-party devices for years; they've just historically been a lot less enthusiastic about it than companies like Spotify and Amazon have been. I would expect to see them be way more enthusiastic from here on.
I'd very much appreciate them making AirPlay an open protocol, enabling any app to freely stream to AirPlay 2 hardware. Are they really benefiting that much from the licensing deals vs the ecosystem it could spawn? They'd still be producing most of the AurPlay receiver hardware people'd buy, just not the transmitting end.
Yeah, I think it would benefit them to make it open, also. It's really hard for me to think of a protocol that benefits from being proprietary, especially if you're trying to build an ecosystem around it.
(I think there's probably a good case along those lines for an open "Internet of Things" protocol that would let any IoT device work with any voice assistant or other controller -- probably by "publishing" a set of control terms for it, like AppleScript dictionaries and whatever the ARexx equivalent was on the Amiga -- but so far I'm not sure anyone's even proposed that.)
But Apple hasn't ever been quite as exclusive as they're painted to be when it comes to peripherals and services. They've had iTunes on Windows for a very long time (yes, it's kind of a trash fire, but it's still there), and that was mostly to support the iPod. They have iCloud for Windows. Apple Music has an Android app, is supported by Sonos and Amazon Alexa, and even has a web-based API (no official "cloud player," but there's an open source one out there which Apple knows about and is apparently okay with as long as it doesn't use the word "Apple" in its name). And, of course, a lot of non-Apple products can receive AirPlay, and they appear to have gotten fairly aggressive in the last few months at moving AirPlay 2 into the third-party market.
So, Apple Services have been on third-party devices for years; they've just historically been a lot less enthusiastic about it than companies like Spotify and Amazon have been. I would expect to see them be way more enthusiastic from here on.