To me it looks more like Overengineered Tracking Prevention to be able to shovel in 'Machine Learning Classifier' for buzzword compliance.
Besides, there is some value in getting widespread blocking. When you're the only one who blocks, that's a signal. When Apple's new doodah blocks mostly-the-right-thing for 10% of the users, that's quite different. You get to be part of a crowd.
Invalidation is hard. Once you accept you have to tread down the road of accepting and deleting cookies and local storage I see no reason to wait 30 days. Why not purge them right on (tab)closing?. If you really care about privacy that is. Which could have been set to be default on the next update btw.
HN has no such partners, of course. But many other sites do, and correlate cookies in order to tie devices together.
So what's the difference? Not everyone has enough time to waste to manually manage exceptions. So they're trying to make it smarter. If it works 90% of the time, it's still a big win, and you can still handle the remaining 10% yourself.