Based on what happened with their e-mail, I imagine if the courts mandated IP logging for VPNs, Proton would still advertise their no-logs policy until they get caught out in a scandal and then silently update their marketing material & privacy policy afterwards. lol
ProtonMail 2018:
Now, Swiss courts have never tried to force us to log IPs, and the law is not completely clearly if we have to comply or not. If we got such a request, we would probably fight it just to test this out.
Did they ever end up fighting anything out? lol