This was discussed primarily in off-list and off-IRC methods, but it was suggested that we install ufw by default but leave it unconfigured so users can more easily set up a basic firewall on their systems without having to install ufw or other software before they can.
This was inquired to me about for my opinions and I was in favor of including ufw as a default-installed package. So was @wxl at last I checked, and @tsimonq2 was the one to start the discussion. Security team also said it would be a good idea when Simon inquired.
Therefore, please add ufw to the packages installed during the installation process. Users can remove it later if they don't want it, or can enable it if they want it to do its job automatically.