I appreciate all of the responses.
I'm going to call and give it a shot. Maybe they won't be as vague closer to the dates than they have been thus far. I know they don't want to say something inaccurate.
If it isn't EPA for those dates (which I'm hoping they'll change due to the expected higher crowds for Memorial Day), then which method do you guys think I should do:
1. Hit IOA early and be in line for the Hogwarts Express and ride over, or
2. Arrive about 30-45 minutes early to the gates of the Studios.
I know it's silly, but I'm bringing my 13 year old niece for her first trip to Universal. I have been to Universal several times, so I don't mind just floating around, but I want her to have the best possible experience with the HP stuff as she is a big fan. In particular, I want her to have the most "authentic" HP book experience, which would be Diagon-Gringotts-Hogwart's Express-Forbidden Journey.
I suppose I just answered my own question then - rope dropping Studio's it is! I want for when she see's Hogwarts to be as awe inspiring for her as it was for me, so no sneaking a peak, even to get Early Admission!