What's the point of asking for a source when you would find it on Google in one minute? Odd way of learning. Not like I brought up some debated viewpoint.
Probably because most of the stuff you'd find in the top search results would include the GP's name.
Just a few sentences later "Automatic tuning in Azure SQL Database also creates necessary indexes and drops unused indexes" - that's not in on-prem SQL Server.
Just a few sentences later "Automatic tuning in Azure SQL Database also creates necessary indexes and drops unused indexes" - that's not in on-prem SQL Server.