[jp10]

I can envision the US Army manning these vehicles with 14 series MOS personnel, which means ADA soldiers. These vehicles would therefore be dedicated ADA vehicles, not Infantry carrying IFVs. Except for shooting bullets at aircraft, MANPAD operation (and all other ADA roles) are not Infantry tasks in the US Army training system.
The infrared signature of helicopters are easier to mask than jets. I would expect the auto-cannon to be the primary anti-helo weapon.