Kevin Tsujihara will reportedly be asked to testify under oath on whether or not he played a role in trying to blacklist Amber Heard at Warner Bros. As THR noted, there's been no evidence presented yet that he tried to do so, and it would've been tough for even the studio chief to remove Heard from the role of Mera, since she already played it in Justice League. (They could've always recast the role, though, just like they could recast Grindelwald in Fantastic Beasts if they wanted to.)