That would help. It won't kill her, but it'd take her time to reform and we could even potentially use that opportunity to trap her somehow.

Without her, Surfer would be far more likely to redirect Galactus in ways to avoid loss of life. We'd have to take her down before he gets his ship's siphons into Braal, though, because as soon as he sinks them in, the planet's core will permanently destabilize.