I work front desk at a hotel and i'm studying hospitality at Rosen Hospitality at UCF so I know a thing or two about these types of situations. I deal with guests who don't pay attention to that type of stuff all of the time. In almost every case i'd say it's their fault, but the hotel just opened. They can still be wrong and not get the perk, but i'm not going to stand behind that desk and be annoyed with someone because they didn't know they weren't getting a certain perk when it's Opening Day. There was a few blogger-types in the twitter-verse who seemed to not even know about this just the other day and were surprised by it.
I don't care how expensive the hotel is or how cheap it is, if the perk has always been available to onsite guests, they'll expect to get it. Those who pay $120/night at All-Stars and those who pay $1000+/night at the Poly all still get EMH, MagicBands and can all book FP+ 60 days out. There is no difference there, so that could also play into guests expecting it.