From what I remember about the convos he had, its more about how, as giantesses, they are not human and are therefore just another monstergirl. As a monstergirl, they are fundamentally different that human females and would have different motives. I'm paraphrasing, not quoting, but that is my interpretation based on my recollection of the convos. I might have misunderstood the reasoning, but he made it pretty clear that he is not interested in giantess enemies for ToT.
Again, I don't agree so its hard for me to really speak for him. I also have not been on discord in a while, so maybe he has clarified or changed his mind since, so maybe someone else has better info.