If they advertise that they will protect their users privacy, then I don't see how complying with government snooping is an excuse. Either provide what you say you will or don't say that you will provide it.
Proton has never said they will refuse a warrant for what your email address or recovery account are. They say that the contents of your emails, calendars, notes, passwords, etc are not accessible to them and therefore cannot be spied on even if a warrant is fulfilled.