"Chappell Roan" isn't a real person, and therefore can't have opinions or agency. "Chappell Roan" is a character invented by the entertainment industry. Famous people, celebrities and nearly everyone you see on TV is not a real person, they're a simulation of a person, but the person they're simulating doesn't actually exist.

If Tom of Tom and Jerry fame posted a video in support of Israel, you wouldn't think "Oh no! How could you do this, Tom?!" You'd think "who cares what a cartoon has to say?" Same thing with "Chappell Roan".