I just speak not as an expert but as a sabra Israeli whose families come from France and Poland/Germany.
I vaguely remember you could get fined in Israel for public ally speaking in Yiddish, but maybe it was just a social thing. There was a huge push to speak Hebrew and be a unified people.
I do know my grandmother would yell at my grandfather for speaking Yiddish at home.
Some Haredim refused to speak Hebrew casually, and stuck with either Yiddish or English on the grounds it is a holy language and not fit for “selling cars and cabbages.” They’ve pretty much lost their war except in NYC.
Oy Vey!...............................