Just to clarify, they could have opened the ride three hours earlier (Disney down the road are opening Galaxy Edge at 7am with Animal Kingdom and Magic Kingdom also opening at 7am to try and spread the demand and attract People away from a Hollywood studios).
But also to add, Universal could have done more to keep down the nine hour queue down. Look at the way Disneyland opening Galaxys Edge, severely restricting access to the area and advising guests on just how busy it could be.
I'm not to clued up on the exact ride, however was this ever soft opened? If there was chances of huge downtime, should they have delayed it by just a little bit to soften the impact.. because ten hours is just way to long for an intamin family coaster no matter how you spin it.
None of this is a problem and obviously different parks and different situations. Just the approaches for guest experiences are vastly different.