Doesn't seem like an unreasonable assumption to me.

Dropbox used to say: "All files stored on Dropbox servers are encrypted (AES256) and are inaccessible without your account password." even though the files were accessible without their account password.

Mega might be doing the same thing: saying one thing to attract early adopters, and changing the marketing language once it gets broader adoption by people who don't care about that attribute. It's dishonest, but it would hardly be shocking to learn that a multiple felon was being dishonest.