https://www.privacyguides.org/news/2026/09/10/new-siri-recap-feature-for-apple-watches-can-create-summaries-of-your-conversations-throughout-the-day-apple-says/

"Siri Recap, the most interesting of the new features, stores a high-level summary of conversations throughout your day. The raw audio never leaves the Secure Exclave, but a condensed transcript of it is generated on-device and then sent encrypted to Apple's servers running Private Cloud Compute, the same technology that powers their cloud AI features.

The claim is that Apple can't access data sent to PCC, but the way the technology works at some point the data must be decrypted in order to be processed. This makes it distinctly less secure than purely on-device processing. Data is included about context like whether the speech was from a song, whether you were at an event based on your calendar data, and even some location information like your city, state, and country.

The summary is then sent back to your phone, encrypted, where it will be stored for 7 days unless you choose to save them."