Google has introduced text customization asset previews for Search campaigns using AI Max.
Advertisers can now view sample AI-generated headlines and descriptions before opting in or launching a campaign. This new feature addresses the concern of not knowing what the AI will generate beforehand.
Advertisers entering a final URL can see up to 10 example headlines and descriptions, generated by Google AI, within approximately 30 seconds. These previews are available during campaign creation in the “Asset optimization” section and when editing existing campaigns.
They come in all languages supported by text customization, applying to most business categories except adult content.

Read the official help page here: About text customization in Search campaigns.
This update was spotted by Hana Kobzová.