What does that even mean lol

Just FYI there’s a standard monthly fee for use of mullvad. This will probably be a feature expansion and will run under that same fee.

Which means this whole paragraph is utter garbage.

"anyone can use mullvad public dns for free. their paid vpn service already uses it so don't set it up separately if you're a subscriber"
Thank you for translating. I use their service and am happy I don't need to make any changes.