You're free to add them then. Not like people get paid to work on the wiki, there's no obligation for it to be made when people are spending their free time to work on it and by people I mean like 3 people last I checked.
Anzu still has her uses. You can use her for anything you can clear without problem because there's no need for the extra damage/defense from Fafnir when you can clear something effortlessly, so at least increase the drop rate. Fafnir's Atk/Def buff can still be gained regardless of her being in a sub slot or not, which is what she's used for, unless you're using a fire or water team. I would assume you don't have any event eidolons by your level and attack.