I dunno... I've always assumed that an Apple refurb was delivered as it originally shipped (as my MBP did).
Refurbs will ship with at least
as good of specs as advertised. They only have that basic selection available on the refurb store, so if they get in a machine to refurb that had a HDD, memory, CPU, or display bump on it, you may come out ahead with a free upgrade.
I've seen people get all of those... additional RAM, larger hard drive, the higher end processor choice, or the higher resolution display, than what they paid for. It's one of the selling points I throw out when people ask me what to get for a computer. "take the money you save buying a refurb, and use it to buy applecare. that will help take away the worry of a refurb, give you a free extended warranty, AND you may get a free bonus if you're lucky".