There's nothing technical to discuss; where's the meat? This 2012 article at least has pictures: https://www.bbc.com/news/magazine-19344978
I speculate the problem is not technical but financial or otherwise; the ML to do this was up to the task at least ten years ago.
Don't neglect the possibility that there are people in power who don't want these records to come to light. Either because of direct implication of people or their families in the stasi atrocities, "national embarrassment", etc
This was a DARPA challenge back in 2012 too. Shredded documents seem more of a challenge than torn.
https://cacm.acm.org/news/darpa-shredder-challenge-solved/