I can’t upvote this enough.

Schools get federal funding for lunches when they follow very specific rules. One of those rules is that you don’t give kids with negative account balances a completely free lunch indefinitely. You can give them an alternative me (sandwich, milk, serving of fruit/veggies), but ok the meal on offer that day.

The parents can just fill out a form to get a reduced or free meal. 99% of the time it’s the parent who just refuses to fill out the form.

If the federal government learns schools are giving away free meals, then NO STUDENT in the school/district is entitled to free or reduced meals.

So, yes. Schools will absolutely and reasonably refuse to give every kid without money a free meal. Because the government requires it.