Its a be a zombie PvP mode, nothing to do with single player what so ever.
Wouldn't call it a "business model" either, all it is, is an extra thanks for pre-ordering.
You are correct Sir. I saw that several times this past year. That's one of the reasons I stopped pre-ordering or buying at full retail at all.
There were very few titles I wanted the last two years that didn't go on sale 30-45 days after launch. It also seems like retail prices are over-inflated and getting worse. Many of the $59.95 to $69.95 games felt more like a $39.95 to $49.95 title to me anyway.
the fact that the FAQ about the mode has been up since september, and in that, they label it as a Preorder exclusive only, and not just a preorder incentive, and since then, hasn't said a word on it, despite a 80 page thread asking for clarification
one can only assume the worst
if it really is a preorder only, and gone after that, they only hurt their own game