Well... it was never hard for melee characters to get combat advantage and there have been all kinds of ways for a group to achieve combat advantage, from anyone you force move, anyone with vulnerable cold, anyone with a common condition like slow, anyone someone is flanking, anyone you hit with a radiant power, etc.
But I am surprised to see it tossed out so easily in these themes, instead of being, say, an encounter power (Free Action, gain or grant CA for a round kinda thing).
It is worth note that things like Guardian and Iron Wolf, even Harper, can still easily beat something like "move up and give me CA". Especially "move up, give me CA, and cost me a few surges over the course of the day"