I am entirely with the “main meal” school of thought. Lunch is, or always was, a “light meal” (“luncheon” or even further back “nuncheon”)
The reference to Christmas Lunch is like a sort of inverse snobbery or reaction to the (shock , horror,) old”working class” reference to dinner as a daytime meal.
I know we are all different and it doesn’t matter what you call it, but a Christmas Lunch sounds a lot lighter than a Christmas Dinner and a bit precious when it’s a restaurant.
34 year old assisted euthanasia
I’m finished my festival poncho