It's not a slippery slope. It's a narrowly defined offense tied to a specific historical crime: the state-organized genocide carried out by Nazi Germany. It's a response to a specific historical responsibility.
The decisive factor is whether the joke attacks the ideology or reinforces it. So if a comedian in Berlin says "the Holocaust didn’t happen" as a punchline, and it comes across as actual denial or trivialization, that can be illegal.
The decisive factor is whether the joke attacks the ideology or reinforces it. So if a comedian in Berlin says "the Holocaust didn’t happen" as a punchline, and it comes across as actual denial or trivialization, that can be illegal.