They could do that, but it's far more likely to be just dry ice. -80 being a class of freezers is a thing because that's what dry ice can provide.

-80 transport often consists of good insulation and a good chunk of dry ice instead of active measures.

I'm not sure it can be used, since it is much colder than -80. I actually hope it can be, because there is quite a few liquid nitrogen facilities, usually near big medical facilities. Dry ice, quite rare. I've seen some for special effects, but declared at a higher temperature than -80.