Like what? They could find a later-model ship, but who cares? The pirates don't have anything that can even remotely take on this ship. A cheap, gun-based littoral-oriented ship is perfect for this role. If looks rather than need drove decisions, they'd have sent a Lafayette-class vessel:
A machinegun-armed Predator flying up and down the Somali coastline, strafing anything that looks like a pirate vessel, would put a stop to this real fast