Google has finally made Android 15 source code available at the Android Open Source Project (AOSP), and confirmed that Android 15 will be available on supported Pixel devices in the coming weeks.
Google also confirmed devices from Samsung, HONOR, iQOO, Lenovo, Motorola, Nothing, OnePlus, OPPO, realme, Sharp, Sony, Tecno, vivo, and Xiaomi will get the update in the coming months. Some companies like vivo and iQOO have already started public preview
Google has only released September 2024 security patch for the Pixel devices (Pixel 6 series and later) running Android 14 that removes third party APK to address security vulnerability in several updates, and the update also improves wireless (Wi-Fi) stability and performance in certain conditions in the Pixel 9 series phones.
Recent rumours said that the stable Android 15 for Pixel devices will be available only in October, and it looks like this will indeed be delayed. Google has already released Android 15 quarterly platform release (QPR) beta 1 for the Pixel devices.
However, if you are in the final Android 15 beta, you can opt out and wait for the stable update instead of installing the QPR update.
More details about the Android 15 AOSP is available from Android
Open Source Project website.