Hmm, what "recently revised libretto" are they talking about?
It's not "recently revised" (your term) it's "recently RESTORED" (the wording on the show's site). And this is legit - it's the recent work of the Rodgers and Hammerstein Organization to get both the libretto and the score/orchestra parts to be as close to the originals as possible. This is the material that everyone now receives when they do the show, and it has nothing to do with the concept of the current Broadway revival.