Fandango pre-sale information is generally not very reliable, and basing predictions on it has been shown time and time again to be a mistake, as most people on here will know.
If you look at other live-action Disney remakes - Maleficent, Cinderella, Oz, Jungle Book - 80M is a perfectly reasonable number to expect. I originally thought 60M or lower as it's a musical, but realised in past couple weeks that that wasn't going to make a difference, so upped my prediction to 80M as I said.