Allegedly the Chasam Sofer said any drosha not in Yiddish is treif.
Actually he poskened that all drashot should be in Yiddish, It made perfect sense in Polygot Pressburg where jews spoke 4-5 languages and Yiddish was a common language, It makes no sense in 2018 where most jews speak english or Hebrew (Or whatever the local language is like french if you are in France). Most people would not understand the Drasha given in Yiddish and there is a good chance the Rabbi cannot give it either.
The Folksbien performs plays and musicals in Yiddish, Many of the actors and actresess are not jewish