Automatic tuning, technology that continuously monitors and automatically improves database performance in SQL Database, will be enabled by default in the upcoming period. Roll out of this change will be gradual and will start from January 15th, 2018. Two weeks before this change happens on any subscription, a notification email will be sent to subscription owners. All servers that do not have automatic tuning explicitly configured will inherit Azure defaults, making automatic tuning enabled. Similarly, all databases that do not have automatic tuning explicitly configured will inherit the configuration from the parent server. All newly created databases by default will inherit the configuration from the parent server.
Automatic tuning has reached the point where it is ready to be enabled by default for SQL Database. Since automatic tuning reached global availability in early 2016, the SQL Database team continued investing in improving its capabilities. Learning from a massive pool of customers who already adopted automatic tuning, we have made advancements in recommendation models, increased the speed and safety of applying tuning actions, and removed obstacles that prevented some of the customers from adopting automatic tuning.
Read about it in the Azure blog.