When pricing & availability is copied from Restaurant_A into Restaurant_B, it will override all the pricing & availability data for restaurantRestaurant_B.
If LateNight and/or some channels (e.g. UberEats) are enabled for Restaurant_A, but not for Restaurant_B, then the P&A will be configured for Restaurant_B for those chanels too. Toggles for Late Night and additional channels should need to be configured separately. How Late Night Pricing & Channel Extension should be configured is explained in detail in the following pages: