I was worried that this was going to cause yeast autolysis, but it sounds like this isn't a factor. I did rack off the primary cake to the keg so it wouldn't be a huge amount of suspended yeast.
I thawed both kegs and they are back in the fridge. I'm going to tap into one of them soon, although I moved a fresh british bitter in when I took this one off and its going to be hard to take it back off, its a favorite of mine.