As for planning days in advance, and requiring notice, that wasn't us at all. But, neither would we let the kids treat the place as a free hotel. Once they were of an age to be somewhat independent, we expected our kids to treat mealtimes with some respect. We certainly weren't going to prepare meals on the off-chance that the kids may actually deign to bother showing up, if they felt like it and didn't get a better offer. Either they let us know in sufficient time to include/exclude them, or they made their own arrangements. And, on several occasions, I issued a lecture about the lack of courtesy and respect implied by saying they would be there, and then neither showing up, nor letting us know they weren't coming. In fact, a couple of times, I read the riot act over that point.
If the kids intend to come and go as they wish, and then expect room service-style gratification of their culinary whims, they can also expect a five-star hotel sized bill for it. If they want to be part of a family, they can damn well treat it with the respect that that implies. If they fail to show up when expected, without even bothering to let us know, they'd better have a good reason .... and that includes a good reason why they couldn't even let us know, not just a good reason for not showing up. "I forgot" is not a good reason.