Last Wednesday, Marvel and Disney+ released two new episodes of their short-form recap series Legends that focused on Mantis and Drax's journey in the MCU prior to the events of The Guardians of the Galaxy Holiday Special which was released today. However, just barely a full day after it became available, the episodes were immediately removed.
As reported by The Direct, the Mantis and Drax episodes of Legends were removed as a result of the inclusion of the deleted scene from Guardians of the Galaxy Vol. 2 where it was revealed that Mantis is Peter Quill/Star-Lord's half-sister. Up to this point, it was never acknowledged as part of the MCU canon.
The revelation in the recent Legends episode was flagged as a spoiler by fans since it is a key part of the Holiday Special where they made it official in the MCU canon that the two characters are indeed siblings. As of the time of the writing of this article, the Legends episodes are still unavailable despite the special already being released.
It is unknown yet if Marvel and Disney+ will eventually bring back the episodes which may happen very soon since the Holiday Special is already out. There's also a chance that they will remove the scene in the episode in order to make it a full recap of the prior events in the official canon.
Regardless of the removal of the episodes or not, the information is already out in the world prior to the release of the special that Peter-Quill and Mantis are siblings. Obviously, it is a major detail about the two beloved MCU characters and it is interesting to see how this key revelation will play out moving forward, especially in the upcoming third film.
The Guardians of the Galaxy Holiday Special is now streaming on Disney+. You can check more details about it here.