That comment was in regards to ufw as it doesn't support adding IPv6 rules by default in commands in older Ubuntu. If you don't enable IPv6 and the server supp

That comment was in regards to ufw as it doesn't support adding IPv6 rules by default in commands in older Ubuntu. If you don't enable IPv6 and the server supports it (odds are it does) all of the benefits of using ufw at all are totally ignored on IPv6.