The raid was the result of the politician (the Innensenator of Hamburg, responsible for the city police) reporting the post to the police. From there they had to investigate (regardless of the NetzDG or any other law governing social media). I agree that the raid was way our of proportion and probably a result of the police trying to please their boss.
The quality of the meat in Berlin's canteens is low. The meals are more expensive and the serving sizes are smaller. Even before this move I saw no reason to eat anything with meat there. BTW: There is already a vegetarian/vegan canteen at the Freie Universität, it's called "Veggie No 1" [1].