This is actually nothing new for Disney, in 1990 they released "Rescuers Down Under" alongside a 31 min. short, "The Prince and the Pauper", and I don't recall people having a problem with that.
I wonder why we didn’t hear much complaints from a movie that was considered a financial failure during the Disney Renascence from over 20 years ago before the internet was public
But I guess shoving a 21 minute short before a movie is totally fine since another movie from 20 years ago only few people saw in theaters did it. I guess no one’s allowed to complain about anything unless we look through the history of humanity to the pre-historic times to see if this problem happened before. I can’t feel pain when I stub my toe because no one recorded Ooga Booga from 30,000 BC complaining about it