"We are extremely happy with the creative direction of Star Trek: Discovery and the strong foundation that Bryan Fuller has helped us create for the series," producers CBS Television Studios said Wednesday in a statement. "Due to Bryan’s other projects, he is no longer able to oversee the day-to-day of Star Trek, but he remains an executive producer, and will continue to map out the story arc for the entire season. Alex Kurtzman, co-creator and executive producer, along with Fuller’s producing partners and longtime collaborators, Gretchen Berg and Aaron Harberts, will also continue to oversee the show with the existing writing and producing team. Bryan is a brilliant creative talent and passionate Star Trek fan, who has helped us chart an exciting course for the series. We are all committed to seeing this vision through and look forward to premiering Star Trek: Discovery this coming May 2017.”Everything is phrased to allow Fuller to save face but make no mistake, CBS gave him an ultimatum. He probably asked for more time, they said no and demanded he either prioritize Star Trek over his other TV projects Starz's American Gods and NBC's Amazing Stories or step down. He chose the more lucrative projects as I am betting he gets no back end points for Star Trek considering its long established and fully owned by CBS where he can get co-creator credit and other incentives if both move ahead with multiple seasons.
Fuller has already written the first two episodes of Discovery and outlined the first season story arc for the new showrunners to follow (or not) so his stamp will be all over the show, especially since he has been involved with most of the set, ship, character, costume, etc designs. Casting has mostly been completed except for the lead role of "Number One". Roles cast include an openly gay human male, a female admiral, male Klingon captain, male admiral, male adviser, and British male doctor. Fuller will retain executive producer credit which will give him some influence on the show but that will influence will be greatly reduced since he will not be involved in day to day decision making. Completing casting and prepping for next month's filming start date will now fall to the new showrunners.
In theory Fuller will remain part of the writer's room and help with story decisions but I would not be surprised if that quickly comes to a halt since timing wise it will work out that American Gods will be completing post production for early 2017 release date, Amazing Stories will be gearing up for its pilot shoot and Discovery will be entering the home stretch to complete final episode scripts and filming. If he could not juggle all three now with one in post-production and two in pre-production, there is no way he could do it next year when all three will be in some form of production, post-production, and promotion phrases that require constant and daily decision making from the showrunner and occasionally the writers to adapt the script for problems that come up during and after filming.
While new showrunners Gretchen Berg and Aaron Harberts do not have Fuller's Star Trek background, they have worked with him in the past on Pushing Daisies. Throwing an odd little wrench in things and a sign that CBS may not necessarily like the direction the show was taking is their decision to add Akiva Goldsman in a "top creative role" who will serve as "producing support" for the two showrunners. I have no idea what that means for the show but will hazard a guess. His writing and producing history is full of successful but not critically acclaimed projects that suggests someone that tends to come in and do exactly what the studios want - no more, no less. He is likely there to punch up the scripts with more action while making sure the studio's will is minded including dialing down Trekism's so newbies to the franchise can follow the show. In addition he will likely push for remaining within and probably further below the current rumored budget of $6-7 million per episode. By contrast I think the average cost of Enterprise episode was around $2 million.
Speculation aside the main takeaway is this - Bryan Fuller is out as showrunner and his influence will decline as the season progresses. Producers Gretchen Berg and Aaron Harberts have now been promoted to co-showrunners with studio gun Akiva Goldsman hired to provide producing guidance. The rumored budget is around $6 million per episode, most of the casting is complete except for the main role and filming will start sometime in November for a May 2017 premiere of the show.