“Making videos interactive with features like end screens and a call-to-action helps viewers learn about your brand or service and take relevant actions. In an effort to simplify our interactivity features across video ad formats, we will sunset the YouTube call-to-action overlay in January 2019 and introduce a new call-to-action extension.”- Google
The new call-to-action extension can be applied to TrueView in-stream ads, and later, to Bumper ads and TrueView video discovery ads.
“When your primary objective is driving conversions or clicks to your website, we recommend using TrueView for action, our ad format that comes with built-in features like a call-to-action displayed while your ad runs and after it ends.” – Google
An example of a TrueView in-stream ad with a new call-to-action extension:
You can learn how to set up a CTA extension for TrueView in-stream campaigns here.