There have been several nods to the X-Men in the MCU since Disney acquired the rights back in 2019. From cameos in The Marvels and Doctor Strange and the Multiverse of Madness to Wolverine's entry in Deadpool & Wolverine,

Despite building up some anticipation for what’s to come, “Captain America: Brave New World’s” post-credits scene plays its cards close to the vest. The sole scene, which arrives after the full credits roll, sees Wilson visit Samuel Sterns (Tim Blake Nelson) at the Raft, a maximum-security prison for superpowered beings.