First, you have to understand the team make up.
In the last game project I worked on, I was one of the lead lore and quest writers (I personally wrote over 100,000 words). Since it was a story intense game, we had a rather large team of writers. We were also the event writers and runners. There was a sound guy, a few artists, and a 3D guy (sometimes), and an animator once in a.... hmmm... I don't recall ever meeting an animator. Then there were the coders. All two of them. They would change the way the quest coding and syntax worked on occasion to add new features, which would generally break all previously written quests.
The game was an unoptimized mess of bugs holding hands using an outdated engine being produced by a completely different team.
When it came to updates, we obviously had plenty of writing to put in. Quests had to go through the coders first to make sure they worked. Books and things were much more easy, and just plugged in. So, occasionally there would be a glut of books and some big events that would happen. Some people were happy about it, others bitched.
"Why the hell are you working on books and events when [bla bla bla] does not work, it crashes on any [brand] GPU, [this this and that] quest do not work, and the animations SUCK!?! But hey, that concept art is sweet!"
So, really, my first question would be "Who is on the team, and what are their areas of expertise?"
Optimization is important, takes a long time, but is tedious and lacks content updates. Artists, and writers can not help here. 3D and animation can to some extent. There would be no perceived game progress while this was in process.
Art and models content updates take a lot of the art and animation department time, some audio, a lot of coding if there are new mechanics (which is why I am stressing more guns in existing classes) and little writing.
Map updates, from what I am told, are complicated and take more time from coding, and a lot of time from 3D art. I have not been personally shown how they make them (yet). Streamlining the process of making maps (tools and easy integration into the game and UI) would take a lot of code time (meaning no updates or optimization for a long while), but would make future additions of map content come fast with possible Workshop integration. However, there would seem to be a HUGE amount of nothing going on while these tools were built.
Game mode updates take a lot of code time, some 3D art and writing, and a lot of balance work.
So, copious amounts of coding is required for almost all updates. The only thing that does not take too much code time is written content. However, your writers, artists, animators, and audio people can not contribute much in that area. So, anything the coders focus on that does not involve their areas will leave them idle.
It is a tough issue to tackle. What the game needs and what players need are often two very different things.
