did they converse in Yiddish?

Take a look at this picture: We see the Munkatcher Rov standing here כשושנה בין החוחים, talking to what seems like Government officials. The year is 1935. Actually it's President Edvard Benes. I assume they conversed in either Czech, Slovak or Hungarian. Or maybe German. Where are all the handlers? the Askoonim? The hoyz bochurim. The Gabboyim? Nowhere to be found. The Roov was all by himself. Did his own talking. No middlemen to interfere or to "explain" what the Rov is saying. Today every 2 bit politician that's running for city council or assembly comes to the Rabbonim and Rebbes and the room is full. The American-born Rebbe'le plays dumb,, or puts on a heavy accent, and some guy in cufflinks and a rolled up beard 'splains to the the Rebbe/Roov what the man is saying.

חדש ימינו כקדם

Who is this Yakov Herzog from Czechoslovakia who so harmlessly pokes fun at Rebbes and their Shabbos tables?

He sounds like in his house they poked fun at Chassidim and their Rebbes. A nice Oyberlender Yingelle whose parents dreaded that he become one of them.