Is ONE PIECE episode 890 filler?
Canon No, episode 890 of ONE PIECE is canon.
#890
Marco! The Keeper of Whitebeard's Last Memento!
マルコ！白ひげの形見の守護者
Aired 23 Jun 2019
Mochibayo compiled this list from MyAnimeList's labels, because MyAnimeList's episode data is not reaching us at the moment.