According to D23, the first Oswald short (Poor Papa), will be included on the Walt Disney Signature Collection Blu-Ray and DVD release of Pinocchio.
Poor Papa was the first Oswald cartoon produced, but much like how Mickey’s Plane Crazy was produced prior to Steamboat Willie, it was not the first released. Their producer, the reviled Charles Mintz, thought Oswald looked to old so Walt Disney and Ub Iwerks produced Trolley Trouble which was released September 5, 1927.
Oswald became a hit so Poor Papa was then released on June 11, 1928.
The restoration was sourced from digital scans of a 16mm silent print that was made in 1930 for home use and discovered in the United Kingdom. This is one of three known surviving prints on Poor Papa.