I don't konw if I can clear things up, but I'll tell what I've understood.
Well, when Maleficent was stabbished by Riku/Ansem in KH1, she gained the ability to travel through time since her hearts has left her body. Then she decided to travel back to the start, before try to kidnap all the seven Princess of Heart. However, something has gone wrong. Instead of getting back to the Birth by Sleep time, she got into the unchained realm. That's something pretty curious because she wasn't even supposed to exist there. She did just because of the illusions created by the Book of Prophecies, or, how we discover later, not an illusion but the "data" from the future worlds.
In this data, she discovers about the book, and up til now, that's the only thing she knows.
"Darkness" said she must return to her on time (her revival in KH2), and that makes me think all of it was destined to happen (in the same way of Xehanort and his pusuing for the Keyblade War). THis "way" to go to the future she was told about, I suppose, will be the same method Ven, Laurian, Elrena and whoever else is going to show up in the story are going to the future, and through this method the "traveller" might lose his memory.
Ok, that's all we konw from the past.
In Re:Coded, Maleficent gets to another "data" realm, the datascape, and by make contact of that again, she remembers about the book, and how it can create worlds.
I can't say what are the implications in the future by now. We know she is after the box, which I believe she will get to know about in KHUX yet. What is her's real intentions depends on what's inside the box, and that's probably the greatest mistery right now. What we know for sure is her goals are gonig to conflict with the Organization's since both of them are after the box.
So many things are yet to be explained... It's too confusing.
I hope I could help in some way. Sorry for the bad English, not used to...