There is no interpretation issue, some people are just confused.

Oura is not claiming E2EE and Oura is not E2EE. E2EE in the health apps would mean that Oura would not see the data. Only user could see the data in their app. Oura's privacy policy states that they do not sell your data, they limit internal access using strict safeguards (like pseudonymization, where your name is separated from your health stats), and they pledge to push back against overbroad government data requests.

Contrast Oura to Apple Health that is true E2EE. Only you and your trusted devices have the keys, Apple can't see the keys, and Apple has noting to give is it gets government request.