Basically if you want to watch the show from the center you need a dining package, if it doesn't matter a FP can work, but I would expect it to sell out by around an hour after the park opens when it is running weekends only, especially if it isn't running on Friday as well that weekend for the foreseeable future since it has been down for about a year and a half and is still so newly opened.
Also a word to the wise, you will probably see crowds higher during the week than on Saturday during that time since the lower level passes will have been unblocked that week and a lot of local schools are still out, it happens every year and the extra crowds during the week usually last until mid September. During this time frame, the days of the week go from least crowded to most crowded:
- Saturday
- Wednesday
- Tuesday/Thursday
- Monday/Friday
- Sunday
This is counterintuitive to most people's thinking, and note once you hit Wednesday you are looking at high crowd levels, that Sunday will also be extremely busy because it is the first day that the lower level passes that are not weekdays only are unblocked, really it is going to be a very busy week.