This is false.

From Wikipedia: "End-to-end encryption (E2EE) is a method of implementing a secure communication system where only the sender and intended recipient can read the messages."

Both ends do not need to be under your control for E2EE.

The point of E2EE is that only the people/systems that need access to the data are able to do so. If the message is encrypted on the user's device and then is only decrypted in the TEE where the data is needed in order to process the request, and only lives there ephemerally, then in what way is it not end-to-end encrypted?