I was waiting for someone to ask :D
The reason for this is because I’m currently in the middle of migrating all of our docs to a new platform and haven’t finished this task yet.
You can see what’s been moved (for v3) and what has been created on v4 so far here: https://themoviedb.api-docs.io/4
Basically, lists are the first set of methods for our new version 4. API wise for lists, the methods are stable. I won’t however commit to the data being 100% locked in though. I have a big blog post about this coming out soon, at that time when all of this goes public it will be 100% locked and ready.
In the meantime feel free to peruse around and see what the v4 lists stuff looks like.