A DC Universe theory links the formation of the new Justice League with the upcoming Superman: Legacy and The Authority movies. Following the announcement that James Gunn and Peter Safran’s DC Studios would create a new DC Universe starting with a Superman reboot, part of the DC Universe’s Chapter 1: Gods and Monsters was revealed. Consisting of live-action movies, live-action shows, and animated series, the initial DC Universe slate is promising a new take on the franchise, with several characters that were not in the DCEU now set to make their debut. Still, one major DC property was lacking from the initial slate – the Justice League.
https://screenrant.com/superman-legacy-dc-universe-new-justice-league-theory/