Do you still need someone in-house if you outsource?

Yes, even if the calendar lives outside: someone in the venue has to confirm the day's dish, the price and whether a table can be promised. Outsourcing without that person fails, because a menu mistake is paid by whoever is at the door, not by whoever schedules. Name one person and a backup, with a daily ten-minute gap for sign-off. Nobody inside looks at the pieces and a holiday menu is announced on a Monday when the venue is shut. The in-house owner's name goes in the scope, with what they decide and what may go out without waiting for them.