User blog comment:Fliu/Chapter 926: Hungry Hungry Hippo/@comment-7614831-20181201083707/@comment-3507581-20181207121541

Well, since Punk Hazard (coincidentally), we've seen a series of until-then unknown facts about Devil Fruits: The Artificial Devil Fruits (and the SMILEs). the Awakening, Special-Paramecia, Undetermined class (Tama Tama no Mi), and as you said, the inheritance.

Looks like we thought we've seen all about the concept of Devil Fruits before the timeskip, then Oda decides to push the limits on what the concept itself means even further...