As reported by our sister site Deadline, during the course of shooting the original 10-episode order for Netflix, AD creator Mitch Hurwitz amassed more material than planned, as he dreamed up new scenes and story arcs on the fly.
As such, Hurwitz — along with producing studios 20th Century Fox TV and Imagine TV — got Netflix to greenlight an additional two to five episodes, bringing the total order to as many as 15. Production was then halted (until late January) so that Hurwitz can review the extra material and decide how and where it will be used to populate additional episodes.
A rep for Netflix told Deadline that as of now “we are not confirming or announcing the final episode count, but we are sure fans will be thrilled when we do.”
Even with the reported extra episodes, the new season of Arrested Development will still drop all at once, on Netflix, sometime in the spring.