There has been no proof that this schematic still drops from those boxes.
As far as I know, the schematic no longer drops and some people are paying huge amounts of credits to get crystals transferred from other servers where someone did have the schematic from the olden days.
I made a thread on this issue, I doubt it will get dev attention, though: http://www.swtor.com/community/showthread.php?t=659523
If you are on The Ebon Hawk, someone will be transferring a shipment of them over from Prophecy of the Five: http://www.swtor.com/community/showthread.php?t=664197
Until something changes, Blue War Hero crystals will remain the rarest in the game, at least depending on what server you're on.