Well, we'll have to wait until after-release for an Actual Clarification...
I just feel you're asking more of a 2pt Card that should really be expected
I agree. It seems fairly obvious to me. You pick your target, then if it's a squadron the attack becomes obstructed. The obstruction will have no affect on your target picking before you declare the target, therefore you wont be able to choose a ship if you are engaged by non-heavy squadron. Though I guess for the brief moment of the attack you might not engaged (this will need clearification since it will affect swarm).