is demon slayer: kimetsu no yaiba episode 63 filler?

During a silent night when the moon shines, Kagaya finally meets Muzan Kibutsuji, who appears at the Ubuyashiki mansion. Kagaya is staying alive day-by-day through his steadfast desire to defeat Muzan, while Muzan dreams of eternity.

What will these two, bound by a continuous thousand-year fate, talk about?