Sure. If they went and hired a few hundred extra people, trained them, put them through all of the security clearance background checks, just to catagorize and declassify thousands of (vastly meaningless) 60 year old Japanese decrypts, can you imagine the bill to American taxpayers?
This thought only occured to me because I'm doing my taxes right now. Or, at least, I SHOULD be doing my taxes right now.
And I know the expense, though great compared to what taxes I paid in last year, are small compared to NASA's annual budget, but declassifying useless old decrypts is not a high-priority activity in my book. Not compared to fixing social security, keeping America safe, etc....