

You know that occupations of universities have a long history in Germany and are both reveered in hindsight and usually tolerated at their time, like the previous occupation of HU in 2017 for Andrej Holm. https://www.hu-berlin.de/de/pr/nachrichten/archiv/nr1701/nr_170131_00
Back then nobody was threatened with deportation.
This is not normal, also not for Germany. Again there is no specific criminal convictions of the people threatened now.
it is not legally binding, but many government bodies treat it like a law, making it tiring to fight against it in the courts all the time.