No, that's exactly how the Industry (also) works. There are different styles of projects, but scripts being finished before any money flows in, is pretty common. And at those point changes are usually small. And usually they also don't plan ahead to become some global hit.

But the point is that Netflix specifically buys productions from different countries, to cater to the fans of those cultures. If they wanted to have a US-ified script, they wouldn't need to go to such lengths, they could just hire some us-asian writer to get another ethnic US-series.