But Orci and Kurtzman might also still be writers, I guess? Or perhaps not -- the title of the article says one thing, the second paragraph another. Either way, this sounds like a creative decision and not a studio mandate.
Excellent sources have revealed to me that the new writers for Star Trek 3 have been found, and as expected Bad Robot is hiring from within the ranks of past collaborators. Continuing with the first two films' tradition of having writing teams, the script for Trek 3 will be written by duo Ashley Edward Miller and Zack Stentz. You know them as the guys who wrote the first Thor and who have a writing credit on X-Men: First Class. They also worked as writers and producers on Fringe, making them part of the Bad Robot family. They also have some Gene Roddenberry experience thanks to their work on the schlocky TV show Andromeda.*
Don't get too excited about certain writers taking their hands off the property - Alex Kurtzman and Bob Orci are still on as writers. I heard that they were instrumental in making the decision about going after Stentz and Miller. What their day-to-day involvement moving forward will be I couldn't say.
Keep in mind this isn't a done deal, so it's possible that someone else could end up getting the gig. And there's no guarantee they're the final writers on the project. But as of right now it's Stentz and Miller's job to lose. And since Paramount wants this movie out in 2016 to mark the 50th anniversary of Star Trek, expect work to begin on it ASAP.
The idea that they'd promote from within their own ranks seems plausible.
There's also some rumormongering in there that Abrams might quit Star Wars.