Useful to whom? Email dumps and other data could be useful for further breaches and attacks against personnel. I'm sure their infosec will be going through everything but they could miss stuff and personal information is exploitable for fraud even with awareness.

Govs like China and aircraft/defense competitors to Boeing probably got a goldmine if they didn't already have their own access. Boeing does plenty of NATSEC and space stuff.

Now that it's out there somebody will doubtless download it and check it out eventually. Stuff that goes onto the Internet rarely goes away.