I have trouble believing that this was a whistleblower. I think a press release is more likely. Of course the next question is by whom and why.
On possibility is that it is supposed to antagonize the German government and public in a limited and deniable way in order to prove to a domestic audience that nothing really changed and no substantial concessions were made.
Or perhaps for some hidden reason they really want to make fundamental changes and escalate the situation to demonstrate that it is necessary.