As others have said, Mullvad is pretty close to (if not at) 100% guarantee... No personal info whatsoever is required to be given when you sign up (including email address or payment information; you can use Monero if you want), so there isn't really anything that they could give to authorities even if they wanted.

Even if they did keep logs (which im 99.9% sure they don't), all that would show is an IP address, and from what I understand based on past precedent, that is not enough to identify a person on its own. But IANAL.

The purpose of these corporate white papers is to inform (impress) potential customers of actual issues. It demonstrates knowledge and implies that the company has the ability to leverage their product or service to meet whatever the challenge is.

I wouldn't say boulder-sized because the meat of the article is true, but yes a bit of skepticism is always useful.