Nitpick: Luxemburg, Belgium (around Eupen), Italy (Tirol) and France (Alsace) are also German speaking countries.

Historically, too: Poland, Czechia, Hungary and Romania, but German speaking communities have disappeared or are in massive decline.

Disclaimer: this list of German speaking countries might be incomplete.

As a Polish person I have no idea how you can come out in public and state that Poland was ever a German speaking country.

you forgot Ibiza ;) "countries with a german speaking majority" might be more correct

Ibiza doesn't count or all countries of the world would be English speaking.