Per [dcl.init]p15, initialization is performed by a return statement. The notion of there being an initializer in this context is used in other parts of the standard (for instance, [dcl.init]p17). The proposed change is not correct, because the initializer may be a braced-init-list, which is not an expression.

Alternative proposed change:

When a variable declared using a placeholder type is initialized, or a return statement occurs inis used to initialize the object or reference returned by a function declared with a return type that contains a placeholder type, the deduced return type or variable type is determined from the type of itsthe initializer.

This is now [dcl.type.auto.deduct] and seems to have been rewritten such that the questionable phrase is gone.