That wasn't a court case, it didn't even go to court. If there are so many, why pick one that wasn't a case? Prosecutors dropped a potential case against a protestor and said it's not a criminal insult because it's (roughly translated) subjective but evidence based?
Germany has laws against being a Nazi. Either there's strong evidence he is one, in which case there should be a criminal finding of fact, or there isn't, in which case calling him that is surely slander. There's no First Amendment in Germany to protect such people. The prosecutor's press release goes off on a political attack on Höcke. They seem to have decided that he's not actually a Nazi but it should be OK to call him one anyway, because they don't like his politics. Very bad levels of political independence from such an office.
The claim about Dresden being a war crime is one I've seen many times. Even in Britain there are people who have argued that. It's like arguing the US shouldn't have nuked Nagasaki. How is that evidence of being a Nazi?
I'm not gonna spend the time to translate more of this. None of this stuff seems legit. The left always call everyone who isn't on their side a Nazi, this whole thing with this guy looks like more of the same. The Nazis openly called for the end of democracy and praised dictatorship. Where is the AfD doing that? This guy doesn't even run the AfD.