It looks like Amazon is starting to hide some reviews to protect against data scraping bots, and in some cases it is affecting real (non-bot) customers.
Were you signed in when you got the message? All of the sorting / filtering / search options are showing up fine for me (as a signed in user).
Were you signed in when you got the message? All of the sorting / filtering / search options are showing up fine for me (as a signed in user).