i have wondered this as well.
I have a similar request; instead of forcing authors to post in a specific category, would it at least be possible to assign them a different default category? ‘Authors’ should in my opinion be given a fair amount of trust, not forcing them to post a specific way. Would be great to avoid a lot of uncategorized posts in a multi-author blog if John and Maria would be given the differend default categories of ‘John’ and ‘Lisa’..
My first week as a WordPress user, do someone else know if this can be done/can be made done?
Maybe this plugin from Owen.
Limit Categories