Digging back a few pages, but I actually know this one! In fact, Dueling Dragons were the first B&Ms to be "quieted down" ('99 for DD vs '01 for Talon).
I used to have a coaster DVD that had interviews with the Universal Creative guys talking about the design process behind coasters at IOA. Basically, DD's proximity to the back of the park (and neighbors) meant they needed to quiet it down (on top of building the big wall along Turkey Lake Rd).
I'm paraphrasing, but the design/marketing spin on it was along the lines of "we wanted Dueling Dragons to be quiet - so it was as if you were on the back of a majestic beast soaring through the air. The Hulk on the other hand is big, powerful, loud, and brash. A ride called Hulk should roar, and it does." Which to me sounds like "it costs a bit extra to quiet a coaster down with the whole sand filling thing, and Hulk was far enough from the neighbors that we didn't have to. Also, without too many mental gymnastics, a roaring noisy Hulk actually fits pretty well with the theme anyway."
So, if new noise restrictions don't get in the way (ask a local, but I'm not aware of any), it would be consistent with the original decision making by universal for Hulk 2.0 to be just as loud as the original.