Don't turn on your favorite local channel expecting to watch the Peanut's "A Charlie Brown Thanksgiving". Apple acquired the rights to those holiday specials in 2020 putting an end to them airing on your local affiliates.
You will need to check it out on Apple TV+ and have a subscription. As a heads up... "A Charlie Brown Christmas" will be the same way. Not to mention "It's The Great Pumpkin, Charlie Brown" too. So don't forget! Happy Thanksgiving!