The preaching was free but the challenges were not due to blasphemy laws, thus more free speech would allow challenges, which we know reduces the problem of bad speech.
> It tells a lot that I never heard historians seriously discussing it in this context.
If you got the first part wrong then the second is only telling in the other direction.
I guess the analysis about Nazis in the Weimarer Republik are far more complex than a matter of free speech. It tells a lot that I never heard historians seriously discussing it in this context.