So, this is a voluntary thing, doesn't involve any certification, has no actual enforcement, and only exist in about half the US states or slightly less.
You're confusing certification with the status of a benefit corporation. Certification has no legal enforcement power other than revoking certification; OTOH, under the model legislation it just takes 2% of stockholders to initiate a benefit enforcement proceeding against a benefit corporation and have court enforce the public benefit provisions of its charter. (Your state may vary -- it looks like in NJ any stockholder can bring such action.)
So long as it exists in the state where Ello is incorporated (which is apparently does), it doesn't matter that not all states yet have benefit corporation legislation.
Yes, benefit corporations are new. If I was going to bet my life on questions of how courts will treat them I might be wary. But as a general matter they seem like they could be a useful way to reign in privacy violations by tech companies by providing a legally enforceable guarantee of behavior.