I dont think it would make any difference if the closed topics would appear at the bottom of the page.
Not that the implementation of your suggestion would look bad, but I dont really feel the need for it. Its easy for me to tell the closed topics from the active ones and the current system has its advantages also.
Im also wondering how this would be coded, because not everyone has the same settings when displaying the number of topics to show for each forum page.
Im going to say no to this

but gl with your suggestion anyways.