That’s a personal statement, not an official one. And not even of the foreign minister or chancellor, but of the one for economy and climate change.
The official position of Germany is that statements done by Ben-Gvir etc. regarding “depopulating Gaza” are unacceptable, which shouldn’t be too surprising that’s been the German position regarding Israeli settlements etc. for aeons. Say what you want about our foreign policy but it’s darn consistent.
Regarding the state calling what Israel is doing genocide: In my estimation, they’re waiting for the ICJ judgement as it’s a juridical, not political, matter. What is political is Germany being the good cop in regards to Israel, someone else needs to be the bad cop, South Africa is perfectly willing to do that, so what exactly are you complaining about.