Using a convoy to deter pirates in small, fast craft with RPGs is like trying to take down that mosquito buzzing around with an assault rifle.
Who knows. Best case scenario they are waiting for a bunch of ships from nations who aren't present but really want to be when they lay the smack down so they can declare their navy part of the glorious, successful pirate cleansing operation. Worst case they are still arguing the finer points of the RoE. If they haven't figured that out yet, they probably never will.
But, methinks if governments really did think these guys were threats, they would be proactively killing them. Not sending a ship to the area and issuing a a press release.
PD