do cakes with cream cheese frosting need to be kept in the fridge

The frosting recipe in question has only 1/4 the amount of sugar necessary to preclude bacterial reproduction (which includes dairy souring) so we agree on this one.

Use this link though:

http://www.food52.com/hotline/14001-must-cream-cheese-frosted-cupcakes-be-put-in-fridge

There was a thread about this not long ago: http://www.food52.com/hotline/14001-must-cream-cheese-frosted-cupcakes-be-put-in-fridge. The long and the short of the issue is that, while bacterial growth is retarded because sugar binds free water which is conducive to it, that is utterly beside the point that the dairy component, which is significant in cream cheese, will indeed sour. You can take that to the bank. Or the refrigerator.