I see this suggestion on my dining confirmation that they sent via email after I made my ADR.
Here's what it states under General Information:
"Guests who have dined prior in the evening may return to California Grill to view the fireworks. Guests will need to present their receipt from dinner to gain re-entry to the restaurant."
I think it is a great idea so that people don't have to really worry about when they dine, they can always finish up an early dinner and then watch the fireworks.
Hope this helps!