Twitch announced that it was experimenting with a new first-time chatter callout feature that lets creators (streamers) and moderators identify and welcome newcomers to their community. This feature is currently available to a limited number of channels and will be rolled out globally once enough feedback has been collected.
This feature will help streamers and their moderators create a more inviting atmosphere for new chatters. It will also help deal with trolls and abusive chatters easily if their first chat message is negative or offensive.
If your channel has the feature enabled, you can provide feedback via Twitch Uservoice. So far, the feedback has been positive.