First and foremost, hello, I'm new to the forum, just registered today but have been following since ascension. For this particular topic I have two theories. Paradise, could refer to being released and helping the current team slay zombies, as we know they all love doing. This is clearly far fetched as I don't think AI zombie slayers would work, but it would be sweet. My second theory, and a more sensible one was actually already mentioned a couple posts above. Someone said that it could be releasing them to the next map which would be set somewhere tropical. The support for this theory comes with the loading screen. In the top left there is a little snippet of Ascension. In the top right, however, there is a similar snippet of what appears to be some sort of tropical leaf. I was unsure what Treyarch meant when he said "paradise" upon release of the achievement list, however, this is my guess as to what the Treyarch team means. Sorry I didn't quote the dude who posted this, as I am unaware as to how to do that as of now, like I said I'm new here and this is my first post. Nevermind think I got it.
-JMO