These changes are an attempt by Mario Huys to create a more balanced Empire map, where no power is seen as the top dog or the underdog right from the outset.
Vincent Mous, the creator of the Empire map, has the following to say about this:
"Empire is not as well balanced as Modern. I feel a 3 fleet Cuba may be ok, but Ungava shouldn't be an army. Too drastic a step. Ungava is not really a city and doesn't make sense as an army outpost, though it does for a fleet. Note that I have not noticed Cuba being too weak on the matches I played back then. However they were 10 player games, not 5x2 team games, so the dynamic would be different."