I know many would disagree but I'm not really interested in having Hawkgirl if she joined the DCU Justice League and I think she would fit better in The Terrifics. I know that everyone wants it because it would make the League just like the DCAU one or the one from the recent comics but honestly I think she fits better with The Terrifics than in the League.
I think The Terrifics in the DCU should be as different as the Justice League and the Titans are. They're the first heroes in DC history and i think their roster should include various members from different generations from the 1940s (Jay Garrick, Alan Scott, Wildcat etc.) or the 60s (Clark Kent, Bruce Wayne, Diana Prince etc.) and Kendra Saunders is the reincarnation of Shiera and would be a let down.
In the Peacemaker Season 2 trailer we saw her still with LordTech so i think by the end of Superman. She and Guy will be still part of the Justice Gang and possibly if we get a Justice Gang/The Terrifics project. I would like it if they explored the DCU connection between heroes and values in their world, preparing the final stage for a Chapter One: Gods & Monsters in the DCU. There can be a place where both teams worked together.