Spatial Audio is a feature developed by Apple. In practice, it is a function that allows you to play surround sound, which is associated, among other things, with the creation of an acoustic space that allows to adjust the tone of the music to the head movements of the user using headphones. Soon, however, a similar solution may be implemented on Android.
Such a hint can be found in the code of the recently released beta version of Android 13. In a folder called "soundfx" there was a mention of support for surround sound. The system code also includes basic libraries related to spatial audio. For now, however, we owe this information to the observations of users, and Google itself has not announced adding such a function to the system. For this reason, we cannot say which phones will receive spatial sound support. They will almost certainly be the latest models from the Pixel series, but it is possible that such support will also be given to older flagships from Google.