This coming מוצש"ק (if Mashiach won't arrive)we won't be eating מלוה מלכה. When else during the year do we not eat מלוה מלכה?
According to Harav Yitzchok Zilberstein Shlita, When Yom Kippur falls on a Shabbos there is no* חיוב to eat מלוה מלכה. Since on Shabbos we don't eat, there is no need to be Melaveh the Shabbos by eating מלוה מלכה
There is a separate Halacha to
eat a Seuda every Motzei Yom Kippur