Last year, Jon Ericson wrote in an announcement about the completion of the responsive design rollout:
We'll continue fixing bugs and starting in 2019 we'll be working on designs for sites with the stock theme. This process used to take a month or more of designer time. With a standard theme, the process will take far less time so more sites will get customizations sooner. Designers will also think a lot less about CSS details and a lot more about how the final design will look. Sites that have been waiting the longest for their design (Anime and Code Golf come to mind) will be contacted earliest next year on their meta sites.
(highlight by me)
It is now end of February (!= earliest next year). The two named sites (anime.stackexchange.com and codegolf.stackexchange.com) still use the Stock theme though and when looking at the community bulletin, I see no announcement/feedback/input posts.
What is the state of the new site designs?
I think this is especially important, as faster design process was one of the core promises of the redesign.