I think who have finished the current chapters of Prisoner of Azkaban in Pottermore have already read this:
I remember the 1st time they did this, it actually less than you think when they say in the coming months, it will be in 2 or 3 months or even 1, but will be probably in 2 months, so I think among February will come out the 2nd Instalment (they did the same with Chamber of Secrets transition from 1st to 2nd instalment, the first was released on 11 July and 2nd was September 18).
as I have told you about my suspicions of how many each instalment will be divided as 7+7+8=22 chapters.
I only got one right which exclusive content would come out in the 1st Instalment, the Knight Bus.
So will be my speculation which exclusive content will come out (speculations, they are speculations not information),so if we go according to the divisions, will be chapter 8 to chapter 14 :
Chapter 8: The Flight of the Fat Lady
I think this will may have exclusive content about the Fat Lady or the paintings being able to move even move to other paintings, now that we started with Sir Cadogan.
Chapter 9: Grim Defeat
I'm sure it won't have none, unless would be about broomsticks.
Chapter 10: The Marauder's Map
I'm sure Hogsmeade will be unlocked in this chapter and also am sure like everyone else suspects that locket in the left superior corner of the screen, it's Hogsmeade and I'm sure we're gonna have also exclusive content about or one of the stores (highest is The Three Broomsticks and Honeydukes), about the Marauders? I doubt it, or is in the last instalment or in the Order of the Phoenix. I think we may have a cool experience with the Maurader's Map, not only in this book but also in the future with it.
Chapter 11: The Firebolt
I doubt there will be any exclusive content, if there will be, maybe Professor Trelawney, even I don't think would be this chapter some exclusive content about her, it would be the last instalment or Order of the Phoenix.
Chapter 12: The Patronus
I know there is lots of fans who think will be here we all gonna have our own patronus, I doubt it. The reasons are first, this is an reading experience, Harry's Patronus is important in the book, I think we are not gonna have our own yet, I think will be in the Order of the Phoenix when the D.A. learns the patronus, so don't have your hopes up, we may have exclusive about the Patronus or Professor Lupin or none.
Chapter 13: Gryffindor VS Ravenclaw
None, unless something about Quidditch, which I doubt.
Chapter 14: Snape's Grudge
If would have exclusive content, it had to be about Snape, but I so doubt it, if it would, it has to be in the Deathly Hallows in Prince's Tale chapter or something about Zonko Store or none.
I hope you liked and agree, you can open speculations by leaving a comment.