The new lines name three sets of laws (California, Brazil, and Québec) but the sentence setting up when they apply is missing. Right now this changes nothing about your rights, and it does not replace the rules about which law governs your agreement. The risk is that it is the leftover piece of a larger governing-law rewrite that could show up in a future version, which can affect where and under which law you would have to bring a complaint.
“Then, these laws apply: - State of California - Laws of Brazil - Laws of Québec, Canada”
What you can do — No action needed today. If you want certainty, check the current agreement at norton.com/legal or ask Norton support what these lines refer to, and re-check the next time the agreement is updated.