I never said the aliasing 'belongs' to insert, or that it has any effect on the insert. I said it's a valid form of T-SQL. That is all I said.

It is a valid form of a select (ie parses successfully) and therefore is is a valid form of the select portion of an insert statement (ie parses successfully).

I never claimed or stated anywhere that it has any effect on the insert, by magically fixing incorrect column ordering or otherwise changing the behaviour of the insert.