The menu label, the page heading and the "New/Edit …" titles all reuse the text from Order: Subscription > Module Subscription: Title in Client Config. Its default value is "Weekly Subscription", so the menu reads "Weekly Subscription" and "Weekly Subscription Groups". Change that setting (for example to "Meal Plans") and the admin labels and the customer-facing module title update together. The same applies to Meal Packs, which follow Order: Packs > Packs: Title.