Spyro: Reignited Trilogy was originally slated for release on September 21st, 2018 for PS4 and Xbox One. The trilogy is set to include the first three Spyro games released on the original PlayStation. Similar to the Crash Bandicoot N. Sane Trilogy, the games will echo the level design and story of the originals but are remade from the ground up with new HD graphics and musical score.
While not outright stated, it’s plausible that the delay is a result of the backlash to the announcement that only Spyro The Dragon will be available on the retail disc, while Spyro 2: Ripto’s Rage and Spyro 3: Return of the Dragon require downloads via the internet.