I think you are ignoring the word “advisory” in the phrase “independent advisory board for the AWS European Sovereign Cloud”.
An advisory board is very different from a governing board.
An advisory board is very different from a governing board.
At worst it sounds like a canary.
What about them? It can be as independent and legally obligated to focus on whatever set of interests you want, if its only an advisory board, then it has no real power. (And, unless there is some guarantee of information other than what the management of the main org feels like giving it to support its advisory function, it can't even serve as a reliable canary.)