I don't know that I'd assuming anything was quick. It sounds like a recipe for disappointment.
My own thinking is that while Bandits as a feature might be quite far along, TFP is likely to slow-burn their approach to finishing bandit AI and also have a bunch of experimentation to do behind the scenes. Then they'd have a number of other things to accomplish. For instance, Bandits might need models and animations. Bandits might require their own unique POIs that would have to be created. Those POIs might need some new custom assets, like barricades for bandits to hide behind. Those assets might need some new supporting code so they AI can figure out where to stand and what posture to be in. Then part-way through somebody might have a neat idea that lets existing POIs treat all zombie volumes as if they were bandit volumes and just changes the mission type and suddenly there's more code and a couple more assets needed. Then maybe the POI designers start to use more Parts in the POIs and need a way for the POI (when it is being placed) to know if it is for zombies or bandits so it knows to place the barricade instead of an overturned refrigerator and a pile of trash...
At the same time, there's bug fixes and optimizations, and some changes from lessons learned about Storms leading to 2.1 and 2.2. There's maybe somebody doing some research in Steam Workshop support and laying some groundwork. There's some debate about how to implement the story and how to overhaul traders that they never quite finalize because that would be for 4.0 so it isn't pressing. There's holidays, vacations, a little bit of staff turnover. There's task dependencies. There's ... Oh look, 6 months have passed. We better start trying to tie up these loose ends folks!
Another year? Perhaps.