You're probably right about that, I haven't payed much attention to when they change or the factors going into them changing, I just know they sometimes do after awhile. One of the many mysteries of MOTD, in my opinion, MOTD is way too easy with all the things to help you out and everything, I'm hoping the next map is a little more challenging, so people can actually test your skills.
Die rise was more of, when you die, do you have the skill to come back, and tranzit was just can you circle zombies. I would like a map that tests your all around skill and devotion to getting far. It'll be difficult, but I believe treyarch can do it.