I can't remember the last time I saw an actual fireworks "show" at Universal or IOA. Universal does have the Universal 360 that they pull out during busy times and holidays and while it contains some fireworks the fireworks really aren't the focus. And frankly, I found it to be tedious and annoying. Perhaps when WWoHP is completed they'll bring some sort of nighttime spectacular to IOA. If they use some of the ideas from the HP books, that could be a really incredible show.
I also think that Universal's location, directly beside residential neighborhoods, may impact what they can do as far as fireworks/nighttime shows.