That would seem to be the main reason for using a temperature regulator, so no, that should work just fine. Although you can do the same thing with a fridge.
One thing that might make the choice easier is the type of keg you got. The vast majority of kegerator conversion threads here are written for ball lock kegs. I have pin locks, and thus most 4.4cf fridges don't work for me (in fact, the discontinued Sanyo 4912 is the only one I can find that *does* without drastic modifications). If you have ball locks (like most, it seems), then either will be fine. But with pin locks, go with the freezer.