The title of "The Delicious Last Course" is a reference to the fact it is a downloadable content, as the first letter for each word in "Delicious Last Course" forms the abbreviation DLC (which stands for Down-Loadable Content).
Cuphead: The Delicious Last Course was actually supposed to be released in the summer of 2019 but due to the Coronavirus pandemic, Developer Studio MDHR decided to delay the game to 2021 and then it got delayed again until it was finally released in June 30, 2022.