This single expression both checks for the equality of its members, but also checks the nullability of both columns. Awesome. A good habit would be to use IS [NOT] DISTINCT FROM instead of every = or <> in every expression (join clauses, WHERE clauses etc.) and you’ll never get burned by those pesky NULLs again!
Koen has a link to a Microsoft feedback item to add this syntax to SQL Server. But that item’s been there for more than a decade, so I would not hold my breath waiting for it to show up.