First, he OP specifically mentions "the Czechs", as in the Czech part of Czechoslovakia.
Second, languages had nothing to do with it. There was an idea that sacrificing a part of Czechoslovakia will be enough to keep Hitler at bay (https://en.wikipedia.org/wiki/Munich_Agreement).
Which Czech part, Bohemia, Moravia, Czech Silesia, or ...? Was it the "regions with German-speaking majority"?
Languages had everything to do with it. "Bohemia became a part of Czechoslovakia, defying claims of the German-speaking inhabitants that regions with German-speaking majority should be included in the Republic of German-Austria."
Second, languages had nothing to do with it. There was an idea that sacrificing a part of Czechoslovakia will be enough to keep Hitler at bay (https://en.wikipedia.org/wiki/Munich_Agreement).