Different ringtones for different contacts, the feature is available from a long time in the Google Contacts app but for that you have to dive into each contact's details page and set ringtone from the overflow menu. While it's not very difficult or time consuming for setting ringtones for some specific ringtones, but Google thinks that a new separate section for contact ringtones might help you set ringtones for more contacts, more easily.

This new "Contact Ringtones" section was spotted by me, back in December 2023. At that time, Google was still working on it and now after two months of work, the feature is making it to stable version with some minor visual changes as compared to initial UI. This is available for me by default in Google Contacts version without turning on any kind of flags.

Here are some screenshots of the feature - 

The feature will be available inside the "Fix & manage" tab. On the "Contacts ringtones" page you can tap on "Add contact ringtone" button which opens the contacts list. Here selecting a contacts open the default ringtone picker (which is usually the "Sounds" app). After selecting a ringtone for the contacts, the contact will appear on the ringtones page with the ringtone name on the bottom. You also have the option to choose a different ringtone (pencil icon) and delete the ringtone for a contact.

You can check your contacts app for the availability or try re-installing the contacts app (which might work). For more such Google apps feature leaks you can join my telegram channel - Gapps Flags & Leaks or follow me on Twitter/X