With ToS, we can assume that everything that is not laid down explicitly tends to err in favor of the company, not the user.
"we store all messages": they store everything and ther s no guarantee of processing, sharing or selling that data
"we store all messages encrypted end to end for sole the purposes of communication and can never access its contents" would provide many more guarantees.
This happens a lot on HN. I remember there was a court order for OpenAI to release ChatGPT chat history, and many of the comments were simply "why are they even storing chat history in the first place? ridiculous" as if that isn't a core feature of ChatGPT.
This is not the case for any modern chat app. When you send a message to someone, it isn't delivered peer to peer straight to your recipient. The message goes from you to the service provider's server from where delivery is attempted whenever that message is processed. Your recipient might be offline, out of cell service, phone turned off, or etc and the central server takes care of that problem. Similarly when you log in to the chat service on the web, on your phone, on a new device etc, the messages need to be synced to you from somewhere, and that's again the service provider's central server. All messaging services do this. These days, some encrypt your messages, but not even remotely all.
