There is no story arc for that. they aren't using ANY of the existing comics/games/books as the basis for these new films. All they are using is Lucas' original outlines and notes for the entire saga.
The expanded universe was never canon anyway except to themselves and even that was iffy. Such works never are. The only things that were/are canon is the 6 films and the CGI clones wars film and series. BUT, from here on out everything WILL be canon though, (which will be a first for any franchise that it's ancillary material will be considered truely canon). They will have a group set up to just for the purpose of making sure everything is consistent and no conflicts arise. especially with the films. Everything that exists currently will be rebranded as Star Wars: Legends. (and possibly the next few books/comics/etc to come out until everything gets sorted)
As for disneyfied, what, like pirates of the Caribbean with them hanging a child in the first five minutes of the third one?
People said the same thing about marvel, but all of those have turned out fine. infact things have been better now then ever.