I just always put it in out of habit from typing out actual MySQL queries (non QoQ). Never was a problem and I always did it. Now running CF11... it requires fixing. Thought it was strange.
I actually didn't even notice that the semi-colons weren't required in QoQ until I ran into this CF11 bug. I also notice the semi-colon isn't necessary for a MySQL query either in cfquery! Seems weird that it accepts them, but isn't required. Just ignores them?