From here: Community Update #5: Week 2
Rather than an ironclad promise to implement this feature this seems like a pretty clear promise to determine the feasibility of it. They were not happy with the feasibility of it back then and they are, evidently, still not happy with it today.
Sure, Vermintide had it, but it didn’t cost them anything in either Vermintide; you hosted your own instance. In Darktide, you occupy server space, time, and energy. Spinning up a whole on-line instance just for one player is a bit silly as it is against the purpose of having servers in the first place.
So, that means, in all likelihood, the checklist for enabling solo play goes:
- Improve bot AI
- Implement a system for self-hosted instances
And that is rather a lot of work for something that is not a priority. Maybe they’ll keep working on it in the background and it’ll just drop one day like Versus, but in the mean-time they have the standard laundry list of balancing and bug-fixes, the PS port, and actual content that they should be focusing on before that.