It does not say “zero-trust” anywhere, it says “zero-access”. The data is encrypted at rest, so it is not e2ee. They never mention end-to-end encryption for Lumo.

Zero-access encryption

Your chats are stored using our battle-tested zero-access encryption, so even we can’t read them, similar to other Proton services such as Proton Mail, Proton Drive, and Proton Pass. Our encryption is open source and trusted by over 100 million people to secure their data.

Which means that they are not advertising anything they are not doing or cannot do.

By posting this disinformation all you’re achieving is getting people to pedal back to all the shit services out there for “free” because many will start believing that privacy is way harder than it actually is so ‘what’s the point’ or, even worse, no alternative will help me be more private so I might as well just stop trying.