This comment nicely sums up one of the things that's wrong with the Apple ecosystem --- apparently, whatever backwards-compatibility Apple does manage to have gets dismissed by developers because "it's old".

...and then they wonder why they can't find the old docs that actually have what they need. Apple thinks the developers don't care, and vice-versa. It's a cycle of negative feedback.

On most other platforms, the assumption is that things will not change between versions, and changes are explicitly mentioned and documented when they do occur, but Apple and its developers seem to have the exact opposite mentality.

I hope you didn’t imply that I’m what’s wrong with the Apple developer ecosystem. Old is fine, as long as it is still accurate. I have spent more time than you could imagine digging through ancient cocoadev mailing list posts and WebKit Trac bugs in order to debug problems with my apps. There is nothing more frustrating than having the only available reference be out of date, and having to synthesize the gaps.

That’s kind of hard to avoid if it’s a physical book and the subject changes names.

I think his point is that it should be documented online, in an ever-green knowledge base...

It's a third party technical book, not an Apple document. No reason to expect it to be reissued because of a later Apple marketing decision.