Sheesh, it's like trying to nail Jello to the wall. Why not just come out and say "Don't worry, Before and After guests will utilize different gardens", or "The number of people allowed in the East Garden before the fireworks will remain the same", or some other not-open-for-interpretation answer?
By sticking that "at the same time" at the end of a pretty definite answer, they've left things unclear. It sounds as if everyone will be allowed into the same area, just not at the same time. Which, of course, leads to the question of when else people would be allowed in the garden, if not before the fireworks?