Currently, Android 16 is in its Beta 4 stage indicating it's core and APIs features have been finalized now it's mature in the phase of the development and their key focus is on Bug Fixes and Stability.
Android 16 Expanding Beyond Google Pixel Phones!

More manufacturers participate in the beta program making it widely available to testers beyond pixel users such as OnePlus, OPPO, Xiaomi, Vivo, Realme and Lenovo.
Unrevealed secret of Android 16
It is equipped with a new type of notification bars for live updates that informs immediately about food deliveries, ride-sharing or downloads directly from the lock screen.
It is designed with Embedded Photo Picker allows for a seamless and private way to share media to apps the pixel users will experience a smoother workflow as there is no need to constantly switch apps. It also possesses a notification cooldown feature lacking in pixel users which manages the notification overload by silencing and reducing distractions.
Android 16 taking Future Path

Another outstanding feature is that it utilizes Bluetooth LE Audio's Auracast technology and can connect to multiple Bluetooth devices simultaneously, and also equipped with ambient volume controls for users with LE Audio.
Possesses Gemini integration, hybrid auto-exposure, precise color temperature, tint adjustments, camera night mode and screen detection, and motion photo capture intent actions.
Its Expected Release Date is May or June 2025
It possesses UltraHDR Image Enhancement and also provides high-quality video recording(Advanced Professional Video, APV Codec Support), has interesting graphical effects with AGSL like RuntimeColorFilter and RuntimeXfermode.
Combined together its going to be a groundbreaking launch, and its expected Date is May or June 2025. Google Pixel is a smartphone brand which can be hardware or software, whereas Android 16 is an OS( Operating System) that is software and is free for end-users. It has features expanded from Google Pixel.