Did it ever come out who pulled them? Was it a choice by Pocket or did Paramount or Abrams make the request?
Not yet, but Pocket's editorial staff said they were holding them back because it was decided to give the film's producers more time to flesh out their universe before tie-in sequels came into the mix.
Given that Pocket had to pay
four authors for manuscripts completed, they certainly didn't hold the books back lightly.
I can't imagine too many authors are working on novels in the new setting if they're not sure when the novels will be published.
Two prequel "Academy" novels for young adults are coming and there has already been
two prequel comic mini-series from IDW and a promotional piece in "Wired".