A plan should bend, not break.
A meal plan stops helping when it starts to feel like a contract. Scullery can hold a loose set of selected meals without assigning each one to a date. When a calendar is useful, those meals can be arranged by day.
A calendar stays optional. A recipe can be cooked next without entering a plan, and a planned meal can move when the week changes. The plan is a shared guide to what the household meant to make, not a promise it has failed to keep.
When the household is ready to shop, the same selection can carry its ingredients forward.