I don't want to jump on the conspiracy bandwagon, but the baristas heard a lot of interesting technical conversations. Also, in the University bar, we use to grab a paper napkin and write in it, but we don't work with classified information.

I think it's just boilerplate in that all SpaceX employees are tangentially exposed to stuff which is ITAR (Rockets = ICBMs)

Only a tiny number of their positions are more sensitive than that (guidance and some of the comms positions, probably, and possibly facilities badging and interconnects for launch operations)