The MCU would be smart to not use Doctor Doom as the main antagonist in Avengers: Secret Wars and save him for the next great saga. Audiences have been waiting eagerly for Victor von Doom to finally make his MCU introduction, and the days seem to be waning given what’s on the horizon. Rumors and theories have persisted as to how and when he may come into play and what his role may look like, including premonitions that Black Panther: Wakanda Forever would introduce him in a post-credits stinger as the puppet master manipulating the war between Wakanda and Talokan. While false, such ideas do portend Doctor Doom’s vast potential.
https://screenrant.com/doctor-doom-mcu-phase-7-villain-not-avengers-6/