We've known for a while that Nova has been on the minds of the MCU's architects. With the future of the franchise teasing more cosmic action, Richard Rider and his Nova Force powers would be a great way to explore the little-seen corners of the MCU glimpsed in the space-based movies. The Russo Brothers even said that the character had already secretly debuted in Avengers: Endgame, only to clarify soon after that they were joking.