It’s syntactic sugar, but oh, is it tasty. From Manoj Pandey:
To make sure I checked the MSDN BOL and found that this is a new feature added to the SQL Server 2016 version. And as per this msdn article this enhancement has been add with theCTP 3 release.
For IF EXISTS option/syntax the MSDN BoL mentions: Conditionally drops the [object] only if it already exists.
This is a very helpful enhancement added to these DDL statements and would reduce a lot of effort and coding lines.
Create IF NOT EXISTS is also a thing. A glorious thing.