I don't know if that's wise to base a whole park day on one meal.
No, it's not. Most of the restaurants are average at best. And, if you are travelling in June of this year, HS does not have enough going on to warrant two full days, IMO.
Look at what each park offers and decide what looks good to your family for repeating. Epcot would be my family's pick since there's so much to see and explore. But, I'm sure others would say that about AK. So, there's no wrong answer. You'll never be able to see it all anyway so pick one and commit. It will be great!
Edit to add: As a first timer, a hopper might be good or it might be an extra headache. You lose park time when you're "hopping" and it's expensive. But, it does solve problems like a park that you don't want to be in all day but want to go back for a specific reason.