Yes, but it can be innocent physical intervention.

With airgapped servers, the question is, how do you install updates? There's almost always a way; IT needs it. With those updates, you can get an attack, if the machine supplying the update has been compromised.

For example, even if the update comes via a DVD, some machine wrote the DVD. If you can corrupt that machine, you can corrupt the DVD. Now you have a way to (eventually) get hostile code on the airgapped server.