WI: Loyal Sudentenland?

POD 1922: A centrist Sudetendeutsche party called the Boehmenich Bund (Bohemian Coalition) manages to get a few seats in the Czechoslovak parliment and join the governing coalition. They run on a moderate platform (official use of German at the municipal level and in schools, bilingual official documents, more or less the the status of Swedish in Finland) and manage to get most of it through although proficency in Czech remains a condition for high school graduation.

1935: The Sudeten deutsche Partei (Sudeten German Party), a rightist party founded two years ago and increasingly influenced by the National Socialists in Germany begins agitating for annexation to the German Reich.

1938: The Anschluss of Germany and Austria brings matters to a head and force a peblicite. The vote is expected to be close, but a clumsy attempt to intimidate pro-Czechoslovak voters by assassinating a Boehmenich Bund leader backfires horribly.

Under the motto "German Brotherhood = Dissent Forbidden!", the proposed union with German Reich loses painfully. Taking this as a personal affront, Hitler orders the immediate invasion of Czechlovakia.

Now What?

HTG (yes, I know this is optimistic)
Well good day... ah, at least original twist :)
I think your POD is flawed, Germans were represented in government as there were parallel german version of all major parties. for example there was a Czech and German Agrarian Parties that differed from each other on local level but AFAIK on natinal level they played together. Root of problem were not politics but competing nature of Czech Germans and Czechs proper, many of our achievements were achieved only out of spite aganist Czech Germans! POD would therefore be needed to be in 19th century and involve more Czech cooperation with Germans and Germans feeling less threatened by Czech economic insurgence ( AFAIK in 17th century all manufactures in sleepy poor province were German-owned, by Czechoslovakia majority of bussines in one of the ten most industrialized countries in the world were controlled by Czechs).