I think it's a brilliant plan for teachers like myself who have to sneak snacks in for the criminally undernourished kids who are borderline FSM, or whose parents cannot / will not take them up. I maintain a fruit bowl and cereal bar bag in my classroom just for them. Unfortunately, the need goes much further than KS1. I still do it for my Year 5 class.
Any teacher knows that a kid who has sat down to a meal and eaten enough will be much better behaved in the afternoon. And frankly, a lot of "Oh, it's terrible quality, I won't let my darling eat that muck" is nonsense. ANY school dinner, be it reformed chicken breast with chips or a burger, is warm, and better than the packet of quavers that consisted of the meal one of mine brought to the school the other day. There is always fruit and salad on offer, and vital carbs and protein, even if it isn't from Waitrose. Please bear in mind that some of the kids go home to a sandwich or less.
And yes, I know apples cost tuppence and feckless parent, etc etc. But i'd just much rather they eat something. I don't mind helping pay for it at all. If you see my pupils sharing their snacks at playtime, you would see that they wouldn't mind either. If you see a hungry kid, you feed them, you don't say,"Oh, but it's a twizzler! And I am paying for it!"
My one worry is that it removes the link between FSM, and the various help schools got to help prop up groups of students, which I think might be intended..........