How do you (re-)enable the "Page Settings and Schedule" choice?
Click the "Settings/Document Library Settings" menuitem for the Pages document library (http://SomeSite
1) In "versioning settings", ensure that content approval is turned on.
2) In "manage item scheduling", ensure that "enable scheduling of items in this list" is checked.
That should do it.
Update: after writing the above post, I found another post addressing the same issue. You can find it here.