Has there been any sign of a proper cover for this release at all? And any news of other novels at all?
Well, the novel is pretty much four months out and we don't usually see a cover until maybe 3 or 2 months until release.
And no news as of yet.
If not, I wonder when they will release news about the next novels... I assume the next ones would come out in 2016... So it would be KH2 early 2016, Days middle-late 2016, BBS or Coded - late late 2016, then BBS or Coded - early 2017 and finally Dream Drop Distance middle-late 2017.
Keep in mind Yen Press is also translating a bunch of novels and manga series alongside the Kingdom Hearts novels. It is best to just wait for news as it comes!
With presumably a KH3 novel following whenever the game is released...
Which of course Tomoco Kanemaki has to write first.