Yes, this is how it should work. But the application must support
Stationery for it to work correctly. If the application doesn't provide
support, the Finder substitutes fundamental actions. What you see are
the Finder actions taken in the absence of Stationery support from the
application.
When you double-click a Stationery Pad in the Finder, you open a copy
of the document. If a document is marked as Stationery, the Finder
checks the application to see if it supports Stationery. If the
application doesn't support Stationery, the Finder creates a new
document from the template and prompts you for a name. The Finder then
makes a copy of the document and displays the copy dialog.
When you open a Stationery document from an application that doesn't
support Stationery, an alert box warns that you are opening the
Stationery Pad itself, not a copy of it. Opened from the application,
you make changes to the Stationery document as if it were an ordinary
document. It is possible in such a case to change a Stationery document
even when you didn't intend to alter the template.
If the application supports Stationery, the Finder won't perform
auxiliary actions. The application takes responsibility for what
happens. The specifications for Stationery support require that the
application copy the template's contents into a new document and open
the document in an untitled window.