Update (Sep 15, 2026): Checked Settings > General > iPhone Storage > iOS again on the release build — Apple Intelligence is now showing 6.78 GB allocated (up from the 3.38 GB seen during beta). So asset download has clearly progressed further since the beta reports. Despite that, Siri AI / Apple Intelligence still does not activate, and the isUseCaseAccessNotGrantedSecure calls still return false immediately with no enrollment attempt (same signature as before). This rules out "assets still downloading" as the explanation — the assets are there (6.78 GB is a lot more than a partial download), but activation/enrollment still never fires. This points even more clearly to a broken enrollment step rather than an incomplete asset delivery. Also worth noting: on the same Apple ID, an iPad Pro activated Apple Intelligence successfully, while this iPhone 15 Pro remains stuck — same network, same account. Still open on Feedback Assistant (FB23788932, FB23961529, 10+ similar reports) and escalated through Apple Support (Case ID 20000128431195 / 102963182419), where I was told this would resolve with the iOS 27 release. It hasn't. Happy to provide a fresh sysdiagnose from the release build with this exact storage state if it helps anyone from Engineering look into the enrollment pipeline.