Most cars ( I didn't say all ) donated to teaching / education facilities are on LOAN not given for free.
I seriously doubt any of them have had there vin removed, IF they have,,, a manufacturer can't just magically just wip up another one. Once a vin is assigned to a chassis by federal law that vin a and chassis are now as one.
Besides, like mentioned these cars are far to old to offer much if any educational value.
Plus once destroyed, Chrysler can write them off at full retail value.