Since I'm a part of their affiliate program, I got a detailed list of instructions concerning Apples move away from iBooks and using Apple Books in the future.
I gave up on iBooks long ago, as the sales were never substantial, and the extra work just didn't justify the effort, and I've instead relied on 3rd parties (currently Draft2Digital, or D2D) to make my stories available on Apple products (personally, SW epub downloads are easier to load and manage), but I'm glad I don't have to follow these guidelines.
They are massive, extensive and tedious! Just reading it, I felt as though I was signing away my first five children!
I wish Apple luck, as they've got a very loyal following, but I'm not about to design any books for their new Apple books program. It's just so much easier making the books readable on ANY format via epubs. Though I'll have to see how my current books appear when viewed in the new Apple Books app.
Again, this is mostly a self-serving rant, as I seriously doubt anyone else is stupid enough to target specific outlets, and only a few of us bother publishing anything, but I just had to vent a bit.