The thing is, while part of the issue was that the Solo: A Star Wars Story blew up Thandie Newton, the other part of the problem was that Solo blew up the second biggest female role in the movie, and the only one being played by a woman of color.
Thandie Newton was a major exception, so a lot of people were hoping she’d stick around.
Once Val was dead, there was only one major role being played by a woman at all.
This would have been an issue in Solo regardless of who was cast in the part.