The upcoming novels that "will weave directly into the new game" got officially announced (though I've heard of the NK Jemisin novel for a while now, I think it was up on Amazon or Goodreads as releasing in November 2016 for some reason).
I love NK Jemisin, though I'm not sure how her style will translate to the Mass Effect universe. I do think her latest books have been her strongest and most approachable, so that's a good sign. The other authors I haven't read anything by, but Catherynne Valente's short-form work seems popular.
Seems like having a bunch of authors as fans of your series can pay off now and then. However, I think a real boon of the Drew Karpyshyn books for the first Mass Effect series was that he also wrote the two first games, making them more relevant for the game universe - good authors can sometimes be wasted on a book that's ignored by the rest of the canon.