As a German I wonder why was this treasure given away to a US museum? Also what is the legal status of ownership of all this? Would have been interesting to read more about this.
It's a pretty monumental effort to transport, store, refurbish and show these massive computers. There aren't a lot of organizations even willing to put in the effort which is why most of this stuff gets landfilled or sent to the recycler. I would assume they asked around and no one else was interested.
I know that as technologists we tend to think of this as "treasure" but most other people think of it as "large metal objects that are expensive to store or landfill." Maintaining, storing, and restoring them on top of that is also very expensive. Usually they'll give them to anyone willing to take them off their hands. We only need to look at the closure of the Living Computers Museum closing [1] to see that most people do not see the value in the history of computing. That's why the CHM is doing such is important work.
In my country museums have accumulated so much paintings and historical artefacts over the last 200 years that most of the collection is sitting in climate controlled vaults.
I bet most of these were German government property at some point. Considering the time period they were produced, they were probably under security protocols as well. That doesn't just expire. You are right to wonder what the provenance and legal standing of this transfer was.
I would argue that ancient Egypt was a bit more distant to modern Egypt, than cold war germany to modern germany. My main argument is, I have memories from that time.
But in this case the answer seems simply, in germany the stuff was rotten and nobody took proper care of it anymore, so I guess it was simply sold? The article is not clear about it, but it lead with "abandoned in a warehouse".