If I had to speculate, I think there could be a couple things at play…
They have been focusing on bug fixes and stability lately as seen in the experimental branches on Steam instead of new features. They added support for MacOS and iPadOS earlier this year, which I’m sure complicates ongoing development.
There have been many game releases lately that may have pulled people away from NMS, like Starfield, Baldur’s Gate 3, Cyberpunk 2077: Phantom Liberty, etc. It may not be worth it for them to invest resources in re-running the expeditions if people are currently focused elsewhere.
Personally, I am on a NMS hiatus until the next expedition or major update.