I'd think that they are obligated TO include the Hobus Supernova as part of the deal with tie-ins is to adhere to on-screen cannon.
But is Bad Robot canon legally the same as Paramount/CBS canon?
Check the copyright page on the 2009 movie novelization or one of the IDW Abramsverse comics. They say they're copyrighted by CBS Studios Inc. and Paramount Pictures Corporation, not Bad Robot. Bad Robot is the production company, but they make it under license from the owners of the property, just like Filmation did with the animated series -- or, in a sense, like Pocket does with the novels and IDW does with the comics.
As I said, it's hypothetically possible that a tie-in publisher might not have the license to tell stories based on a given part of the canon; but even if that were the case, I think the publisher would still be constrained from contradicting any major element of the canon, even a part they couldn't specifically reference. For instance, IDW doesn't have a VGR license but I doubt they could claim that "Endgame" never happened.