This would be cool for importing blogs, but it would cause havoc for ordinary notes.
Discussion
I wonder if I post a note in the future will it stay at the top of the feed until it arrives on its date?
Maybe doing it in a similar way to how broadcasts are done?
Definitely interesting for sites like habla.news.
This also makes me realize that we can't prevent a client from posting notes with random dates. Maybe we need a NIP that sets some parameters about dating, backdating and broadcasting.