They created a brand new microkernel with Linux ABI and driver support in containers? Or... did they just slightly fork Linux and pretend they invented it?
It's not, they have meanings and they can't just make up something different and pretend it's a microkernel when it isn't. That doesn't make it bad, it's just not what they are claiming. It also obviously isn't IPC, despite their continued use of the term throughout.
Also their isolation says it's ARM Watchpoint which is a debugger support? Maybe they are trapping unexpected address writes, but that isn't doing much for restricting privileges. It also lists Intel PKS, which Linux already supports/uses as well...
They address at length why they don't use a traditional IPC for the most sollicited part of the kernel.
It being or not being a microkernel is not in itself a very interesting take. What's interesting is how useful or not what they do is.
Some might argue that this is intentional, but to me, this more likely shows that HarmonyOS is just a hard fork of Android without sources released and, likely, with their own virtual machine implementation (ARK instead of ART).
Looks shockingly similar to Android Studio including the exact same program layout on the filesystem and SDK compatibility selection.
ArkTS itself looks new enough, but if it turns out to just be something like Flutter, running on an otherwise Android OS, that doesn't look like it would be surprising
And Flutter was initially based in React before adopting Dart, while Compose was Android's team response to the internal turf wars at Google.
It is to be expected that when forced to not use Android any longer due to politics, they would make a platform that eases the effort of developers with Android skills to transition to a new platform free of US politics.
Some might argue that the software has enough changes in it to be considered a distinct OS, but I'd rather just call it a hard fork as I had the impression that this was a more accurate depiction of what's really going on behind the scenes.
Especially if that was just one component of a supposedly entirely new OS that quickly replaced something decades established without regressing user experience or features