I actually called WDW reservations to ask about this. The very nice lady on the phone told me I didn't have to make reservations to see Remy -- he would be appearing outside in the garden area behind the perfumery in France. She told me to get a park schedule for listed times. As for seeing him in Chefs de France, she told me Remy would be appearing at different times throughout the day, but that there was no guarantee I would see him while in the restaurant.
So I'm keeping my reservation but I'm getting that park schedule.