May already exist. CBATG (well I did but only found one ‘unpublished’ plugin).
A plugin that will control the publishing of posts, only releasing one every X days.
For example, I could write five posts in one night, hit publish and forget about them. The plugin would publish the first one immediately, then set the date on the second one to X days from the first, the date of the third one to X days from the second and so on.
It would need to check the dates of previously published posts to get the gap between the first post and the most recently published one… in fact that’s all it would need to do. Check the db for the last published post, and change the date on the next post to X days from that. As WordPress will pre-publish to future dates that’s all it should need to do… Hmmm that doesn’t sound too hard actually. For someone else, obviously.