Agreed. It does seem a mostly US concern. Certainly we don't have the same level of handwringing over it here in the UK.

When Ghost in the Shell was remade by Hollywood and criticised by some in the US for "appropriation" in having a white woman (Scarlett Johansson) in the lead, I saw a video showing Japanese people on the streets of Tokyo being interviewed about the film. Far from being offended, they were massively honoured that Hollywood had chosen to remake their film, and thought Johansson was a great choice for the lead. When asked if they found this appropriation offensive, they were either bewildered or simply laughed.

Incidentally, the Japanese have sometimes remade films they consider great as well. For example, there's a (suprisingly good) Japanese remake of Clint Eastwood's classic Unforgiven, with a Japanese cast. Cultural appropriation or just a good film? I think the latter.