The book isn't out yet, but I've been reading and apparently it reveals when the Jedi Massacre happened, five/six years before TFA takes place. If this is true it definitely changes a lot of the "fanon" timeline a lot of us have. Means Kylo was an adult when he killed his fellow students. Rey would have been 13/14, etc.

There are also talks that the aithor wasn't allowed to look at the script and this might have caused the timeline fail, but I also feel like Disney wouldn't let something so huge pass. Idk. What do you guys think? Yay or nay?