It's the other way around here: Everything is public except where it's made clear that it won't be (e.g. email address, password).
For what it's worth, your instance of choice is particularly negligent in regard to informing its users. Compare lemmy.today/legal to lemmy.world/legal, or their respective signup pages for examples. There's little that Lemmy itself or the community at large can do about that 😞
Just standard clickbait, but sounds more serious because we understand the extent to which they're going out of their way to bend and withhold the facts.
They don't seem very active, but you can try reaching your instance admin at https://lemmy.today/u/mrmanager