Well if the books aren't allowed to touch anything from the films and Abrams takes as long to get film number 3 into cinemas as he has Into Darkness then they're going to have to slow down eventually regardless of what the editors want.
Since the Hobus Supernova event occurred in the Prime Timeline, I see no legitimate reason - nor have I ever heard one thrown out by anyone officially associated with Trek Lit - that the event cannot be addressed in Prime Timeline books. The only constraint I could see would be if whatever Pocket puts out has to substantially jive with the Countdown comics.
I believe the edict is that nothing in the nuTrek timeline can be touched at the moment by Pocket - outside of film novelizations. That does not include Hobus, which is specifically stated to have occurred in the Prime Timeline.
Of course, I am open to correction...