It's a lot of "clearly that's how it happens" because from the author viewpoint (pro gold holdings), anything else would not make sense.

E.g.: "It seems clear that they negotiated hard with the US and acted rather shrewdly." does not provide any source for the statement, and it's the same for almost everything in the article, just speculations.

One could also imagine, that Germany plans on lowering their gold holdings and having them on account at the FRBNY would be a convenient thing to make that happen.

There is very litte content in the blog so very little to not trust. The situation as described is hardly news. Foreign countries have troubles repatriating gold and that is hardly surprising. The US are in a better position to negotiate here.