Then put it in the uesp. Also, there are two types of easter eggs, references to real life, and references to previous games. This may already be in the latter
In Skyrim there is a book called "The Oblivion Crisis", which is about the Oblivion main quest. Considering it's a reference to a previous game, I take it you consider it to be an easter egg?
Or the Dark Brotherhood itself, is it's very existance in Skyrim an easter egg considering they were in Oblivion too?
Or what about Wabbajack? That weapon is both in Daggerfall, Oblivion and Skyrim. Is that also an easter egg?
Or leather armor, as generic it can be, it's available in both Oblivion and Skyrim. Is that an easter egg? Or a reference to an 80s game which also had leather armor in it?
No, they aren't. References to older games aren't easter eggs. And putting it on UESP would be a bad idea.