The term "German Flute" was once used a very long time ago in England for a while to distinguish the transverse flute from the end blown flute, namely the recorder. However as the recorder fell out of use as an orchestral instrument the term became redundant and died out.

The best that can be said is that "German Flute" is an archaic term - very archaic - about 300 years out of date.

Yet another of WAV's attempts at misinformation.