Quasi, I think you underappreciate the phenomenon that is Hamilton. In my trips to Europe this year, the first thing people wanted to know when they find out I am from new York (at least prior to the election) is if I have seen Hamilton. And these are not theatre people. When I was in Amsterdam in January, at least 4 people wanted to know about it.
You can't compare the Dutch and the Germans. The Dutch may have heard about it. I promise you a random German who isn't interested in theatre wouldn't even know that there is a musical with such a title. Most Germans only think of Cats, Phantom of the Opera, Lion King, Starligh Express and maybe some classics like West Side Story when they are asked about musical theatre.
we are not talking about random Germans; we are talking about actual humans. And random is never a good sample because most people in every country are not in the theatre-going demographic. But whatever.
I think Germany separates itself more from the (showbizz)world, their own german music is most popular there, and they dub every movie into te german language, etc), while in Holland all the movies stay in English and there is British and American music in the charts etc.
That is true but I don't see how it relates. Culturally aware Germans know the major American cultural news just as culturally aware Americans know the major German cultural news. My point is that Hamilton is a worldwide phenomenon in a way that, say, even shows like Book of Mormon are not. To not be aware of it suggests ignorance.
"Despite being an amazing show, I am really wondering how it will be perceived by Dutch and German audiences who do not have any affinity with American history."
I'd be willing to guess that Dutch and German (or Nigerian or Japanese or Argentine) audiences have at least about as much affinity for American history as an American audience does.