Firstly, there were changes in direction after IDJMG split, maybe she decided not to be affected by them and just move away (to a team managing her since 2010). Although I don't see significant changes, because Steve Bartels is still the director of Def Jam, but who knows? Then, it seems like Def Jam played only formal role to her, not like they've been involved in creative process directly. Also, Def Jam is still involved, I'm pretty sure the situation actual for past 2 years is just fixed officially now. I hope, if there are changes, they are for better (not for worse promo/pressure on creative process/ label forcing her to do more stable image, etc). Finally, I was pretty sure she did it at least last November, but all these sources
suddenly noticed the page on Roc Nation site updated, like, in 2012... (I mean, "Legacy" section, just check the data)