A ton of variables exist GMan so it is impossible to tell. If they were indeed buried with the intent of later recovery, they may have been gently placed in predug pits or if they were indeed left in the shipping crates and just shoved in, they could be junk because of all the voids created that allow air and moisture to do their job. In the aircraft I have seen or worked on recovered from burials it can be a mix bag. Usually the exterior skin is lost, but the structure is generally in very good shape. Either way, these aircraft could very well prove to be amazing time capsules, or bundles of corroded metal suitable only for display as is.... It all depends on a variety of factors environmental and placement factors.
I am crossing my fingers, hoping they are usable!