I'm sure this depends on the team, but I've actually heard from someone who works there that Netflix views working overtime consistently as a red flag? As in, everyone is supposed to be a superstar engineer, and not being able to finish your work in 9-5 makes you look bad?

I can't speak for everyone at Netflix, and as you mention it may depend on the team, but in my team I don't think anyone cares. Why should it matter how many hours someone works a week, as long as they do a good job overall?