He could have returned as Mysterio in No Way Home, but now, it seems he is truly done with the MCU. So, James Gunn could certainly pick him as one of the biggest names in his DCU movies.

X-Men: 10 Actors Who Could Play The MCU’s Magneto. Any of these actors could bring magnetism to the magnetic mutant! by Michael John-Day. Aug 25, 2022 August 25th, 2022. WhatCulture.