OP stated “I maintain that”, meaning that the assertion is a theory of his/hers. And I see nothing wrong with that, nor with referring to Yiddish as a Jewish language.
You may disagree with the assertion, but that doesn’t make it bigoted. It is correct that there was a large population of Jews settled in the area, and there is a commonality in that both accents include an uptick in pitch at the end of sentences.
I disagree with the assertion. Of course I do. I did the research as well.
The problem with your argument is that it wavers. Look at it.
First you say it was a wondering, which is not factual. Now you say assertion, as if that was your original point.
Wondering and maintaining are two different thing.
You can say you agree with the point maintained, but you are both in dream land because it is an opinion, not a fact, and there are zero facts behind the opinion.