They had a bunch of people debate the subject:

My sister is adopted and from a different country than me... it wasn't an issue for us growing up. It did come up over time, but we both worked through it.

It is pretty amazing to me how experts who have never experienced adoption (as a parent, a sibling or a child) feel so confident weighing in on it. In any case, haven't there been enough trans-racial adoptions that we can just ask the adoptees and the parents how things worked out and see how things are going?