Educational discounts do not apply to refurb products.
Refurb products come with the same warranty as new products, and qualify for AppleCare
Refurb products have a changed serial number that identifies them as refurbished
Refurb products come with whatever OS version and software they originally shipped with as new
Refurb products come with the same items in the box as new products, only the box is a plain one, not the new box.
A refurb product could have some cosmetic signs of prior use, but rarely do
A refurb Mac may have some cycles on the battery, but not a significant enough amount to affect usable life
The refurb store inventory changes frequently, sometimes several times a day, and doesn't have any direct relation to upcoming product releases. What's available in the refurb store is determined by what has been returned to Apple.
If you're looking for a particular item, refurb.me can alert you when it becomes available.