Happened to me when I saw a book on the US site, I wasn’t able to see all reviews, but there was a button to sort-of “apply” to get approved for seeing all of them.
It took five days, then I got this email.
Interestingly, they’re not doing this on the European site, you can still see all reviews there.
So that’s actually interesting though. I’m not necessarily condoning this behavior. But if they have identified that unscrupulous, fraudulent outside parties are potentially manipulating the reviews, and that is what’s causing Amazon to block the reviews, then that might actually be a beneficial move on their part. It’s Amazon, so I’m inclined to think they are the ones behaving badly, but this is at least a possibility.