My answer is not at all related to Epcot on your date in question but just Disney ADRs in general. Our last trip was in November 2022, the week of Thanksgiving specifically. We were able to book everything that we wanted for our entire stay except for breakfast at Boma on our checkout day which was the Saturday after Thanksgiving. For context, we were arriving the Thursday prior to the holiday so this was not early in the trip. But it was the same as what you are seeing, there was no availability for any mealtime for several days toward the back end of that trip. We just kept checking and, if memory serves, it took a week or two but one day times just opened up but when they did there were ample options for us to pick from.
I might try snagging something else just in case, unless you would rather do QS, but in my experience this sort of thing happens at Disney restaurants sometimes. Good luck and enjoy the trip.