I think Diner is too small, which is why it was a Turned map. The Power Station is real small, too. I wouldn't see that as anything. But I was wondering why Origins was just...Origins. No Grief mode for it. Which with the map being rather large, I guess it would make sense. But, I was disappointed none-the-less. I also was hoping the Remington New Model Army to make a release in Origins, but that didn't happen either. 
I was thinking about stuff like this the other day. Like during interviews before the games released, they bragged about bringing zombies into the MP engine. Which, we did get to see 4v4 and a temporary 8 person tranzit glitch, but nothing really so extravagent. I was thinking they would've done a MW3 kind of thing and just had some MP maps available for a zombies mode. But then I assumed it couldn't be done for ,'memory limitations' that gets kept throwing about. Ha ha.
But besides that, It'd have been cool. Sure, we wanted story, but what should've been focused to bring all of us back is a more fun Co-Op experience. If Cell Block could get inmates and police officers, and other maps get CDC/CIA, why not just bring them back into some MP maps without creatiing eerie atmospheres or change to the map, besides adding rebuildables to windows(Or don't; Like Nuketown.)
It would've been a good idea, and would have kept people playing small survival maps, just for fun, while waiting on the next bit of story.
Here's to hoping maybe we'll get to see a mix of both worlds to the next Cod game with a zombies mode. 