Facebook has changed pages slightly so that page managers can now see who posted content to the page. Only page admins can see the information.
This is a good move. Because page administrators are effectively anonymous to the general public, any page with multiple administrators could contain content from any one of them.
If you create a page and you have multiple administrators, now you will be able to see, on any post, which administrator created that post.
This will make it easier to see who is doing a good job, or not.