I assume what they mean is that - they might have to log connections to their service (like with ProtonMail), but they won't have to provide what data that user account has accessed through the service, same as they didn't provide the actual emails of the account in question, but "just" the connecting IP.
> Under current Swiss law, email and VPN are treated differently, and ProtonVPN cannot be compelled to log user data.
https://protonmail.com/blog/climate-activist-arrest/