I've been reading through Signal's government requests and couldn't find a similar section on Mullvad's website. I'd be curious to read about them if there are any. It would seem unlikely to me that Mullvad has never received any kind of court order for information about a user.
They even stopped allowing customers to pay with credit card recurring payments because they didn't want to store customer payment info that could harm their users.
I currently pay Mullvad with a recurring charge on my credit card.