Here's what's happening: Only people who booked the package are GUARANTEED admittance to Harry Potter. The soft openings will begin well before the package dates anyway. There are so many things that go into this ride that the soft opening period should be lengthy to get them all ironed out. When they tell you that you won't get access, it's because the ride won't technically be "open" even though it will be running, when possible. If they start telling people they'll be able to ride and then the ride shuts down (which happens frequently in soft openings), people are livid.
If you really think that the only people who will be able to ride this ride before the grand opening are a few hundred people who booked a package for three weeks prior, I don't know what to tell you. There is NO way the ride would be ready for grand opening if those are the only people who could ride it. You need to practice running full capacity. This is not going to be a fly by the seat of your pants opening for Universal.