Delve Item Login Campaign

I was wondering why the Cehuetzi and Yggdreants items are never included whenever the Delve items are put in the login list? These items are important too for people returning and people that want to craft Oboro items like the Dunna or want to reforge their relics. Any reason why these 2 groups are left out?

You'll probably see Delve II items next month. My guess is they are just drawing it out instead of offering all of it like the usually do.