Note that these rights were not at all guaranteed pre-1919. Censorship of speech and of the press was practically institutionalized in the German Empire. It makes no sense to argue that the rabid anti-Semitism of late-19th c. and early-20th c. Germany was a result of too much freedom; on the contrary, it was directly carried over from previous authoritarian government, The Weimar constitution ultimately came too late to really improve on that state of things.
And it wasn't just Germany either. Remember the Dreyfus Affair? That was in France pre-WWI. Dreyfus was framed by the authorities for a crime he did not commit, and initially got a life sentence before widespread public opposition led to a reopening of the case and ultimately to his exoneration. This whole ruckus shows that the very idea that anti-Semitism was something that should be opposed could be considered radical and anti-authoritarian at the time even in "civilized, developed" La Belle Époque France, never mind Germany! The mindset was wildly different from what we'd expect today.
And protections against ant-Semitic expression were too weak as evidenced by Nazi regime coming to power by being elected in democratic process.
Another source: https://encyclopedia.ushmm.org/content/en/article/nazi-propa...
"When the Nazis came to power in 1933, the German constitution guaranteed freedom of speech and freedom of the press. Through decrees and laws, the Nazis abolished these civil rights and destroyed German democracy. "
But I concede that there are exactly opposite views.
After all it's history so anyone is free to make stuff up about it that fits his narrative.