Some of the casting announcements for Superman: Legacy don't involve characters related to Superman. Instead, they're other DC heroes, including Isabela Merced's casting as Hawkgirl. While her presence in the movie suggests a bright future for her in the DC Universe, said future must carefully ignore a popular direction with Hawkgirl in the DC Animated Universe.
Source:https://www.cbr.com/hawkgirl-dcu-green-lantern-mistake/