I think the problem with this group is that it's using the wrong meaning of recruitment. Recruitment, the way it is used in the article they're citing, means actively employing someone in the armed forces. The law is there to prevent nations from sending toddlers to the front lines as kitted-up combatants. It's not addressing trying to dupe gullible meatheads into thinking the army is cool. The US Army, whatever you may think of it, does not send people under the legal age to war. It's not violating the law.
That said? Yeah, AA is a recruiting tool. A bad one at that, but it's there. But I would also wager that someone would have to be pretty low on the mental faculty list to take that game and pull from it "The army is cool and has no downsides whatsoever!". Not any more than just about any war movie ever made, at least.
This is just yet another case of soccer moms trying to feel important. None of them buys, plays, or in any way invests in video games anyway, so nobody will really care. Hell, none of them even pays attention to ratings -- do you know how many times I've been in a game store hearing some lady, toting around a 10-year-old, screaming to the cashier about how he sold her some filthy GTA game? With her being fully informed at time of purchase what it was?