Source: Curse

I noticed that a number of items in the "Toys & Items" section that lead to mounts/pets/toys remain on the tracking popup even if you already have them. Primal Egg, Fel-Spotted Egg, All-Seeing Left Eye, All-Seeing Right Eye, and Nightwreathed Egg are the ones that stand out to me.
I think I got some of these prior to installing Rarity, which may be why they didn't trigger and fall off the list (though I know I have gotten several Primal Eggs since then and I think a Nightwreathed Egg or two, and those never seems to fall off).
I'm wondering if it would be helpful and possible to automatically hide them if the resulting collectibles are all acquired. Just a thought. Thanks.

Another report, this time on Discord:

I think this is a bug - I just got Rarity. I have the toy "All-Seeing Eyes" but it lists the two parts of it (All-Seeing Left Eye and All-Seeing Right Eye) as needed.