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,

According to longtime Marvel producer Nate Moore, 'Captain America: Brave New World' lays the groundwork for the X-Men in the MCU.

That's because Captain America: Brave New World brings adamantium into the fold. The substance shows up in the body of the Celestial that emerged from the Indian Ocean in Eternals. Now, it's the cause of international conflict, as major world powers try to control the world's only known adamantium supply.