So evidently the change in Val’s fate came down to time constraints during the filming of Solo: A Star Wars Story. Apparently in the scenario where Val was kept alive, she wouldn’t have factored into the rest of Solo’s story, but the door was open for her to return, be it in Solo 2 or another Star Wars project. But that’s not what happened, and Thandiwe Newton was dissatisfied with Val being killed off even during Solo’s principal photography. The actress continued:
Source: Cinema Blend