But regardless of semantics, they're being transparent on the project's status.
Every project has cons and they should embrace it and call it out like this project did instead of forever targeting a perfect library but nothing is perfect. It serves its purpose.
I am not sure if they are telling people not use it just because chrome now says to exclude it or they came up with it independently.
Independent. The maintainers have been recommending other alternatives (like Luxon) long before Chrome started to advise users on it. Moment has been in maintenance mode for a while now, this is just an updated confirmation of the fact, I'm guessing because users kept asking.