Ad suggestions are recommended versions of existing ads you can use in your ad groups. 

Starting June 1, 2018, you may see ad suggestions on the Recommendations page of your AdWords accounts, and can choose to manually apply or dismiss them. Depending on your account settings, you'll get an alert in AdWords and receive a corresponding email every time Google suggest new ads. You'll have 14 days from the notification to review them, after which the ads will be automatically enabled unless you choose to remove them.

These ads will be created based on information you've provided in your existing ads, such as your headlines, descriptions, ad extensions and relevant information found on your ads' landing page. You can edit, pause or remove ad suggestions at any point.

 

Opt in or out?

 You can opt out of automatically applying these ads in your account settings. You can opt out accounts in bulk by going to "Management" on the Accounts page in your manager account.

Google Ad Suggestions
 
Google Ad Suggestions
 
Google Ad Suggestion options