Certain characters can be left out of the ending if you either let them die or chose not to import them into the Final Tale. These are the Eblan Four, Calca & Brina, and Golbez. The affected scenes & lines as well as the visual appearances is merely cut, and are left otherwise untouched with no dialog alterations.
There is only one minor dialog change in the ending depending on your actions. If you do not save Leviathan and Asura, they will appear in the ending anyway, and their initial lines of dialog, as well as Rydia's, are altered to reflect this.