Kazuhisa Wada, the producer for Persona 3 Reload, uploaded a developer message discussing the Episode Aigis: The Answer DLC. You can watch the message, with English subtitles via the official Atlus Twitter (X) account.
In his statement, Wada explained that Episode Aigis takes place after the main game, as well as gives context on the history of The Answer. The Answer first appeared in Persona 3 FES, which was an expanded and enhanced version of Persona 3 similar to Persona 4 Golden or Persona 5 Royal. Because Persona 3 Reload is a faithful remake of Persona 3, he felt that the game would not be complete with Episode Aigis, which concludes the entire story.
According to Wada, the development team intended on including Episode Aigis as part of the base game. However, they were unable to do that for “challenging reasons,” and so gave it up. However, after Atlus announced Persona 3 Reload, many people around the world requested for The Answer to return. He is sure that The Answer will satisfy people who already played it, and those who will be experiencing it for the first time.
Persona 3 Reload is readily available for the PS4, PS5, Windows PC, Xbox Series X, and Xbox One. Episode Aigis: The Answer will appear as DLC in Persona 3 Reload as part of the Expansion Pass in September 2024.