They weren't tossed. The other pieces in each set are not etudes. In Op. 49 (3 Morceaux), the pieces are (in order): Étude, Prélude, and Rêverie. For Op. 56 (4 Piéces), the pieces are: Prélude, Ironies, Nuances, and Étude. You never hear of the others because they aren't etudes, and they basically never make it to CD, except in the Michael Ponti set and maybe like 1 or 2 others.