As far as I know, one of NTR's main devices it centers around is cheating. So if one officially rejects Zoey, Jacob needs not ask for permission even. It wouldn't be NTR at that point, no cheating. Basically, if MC picked a GF in EP8, and ALL the other LI's hook up with someone, it's not NTR. It's just MC closing doors on LI's, and LI's turned to NPC's are just viable for anyone at that point.
I have never been into that as a genre, but I once started reading about it since I saw NTR and wanted to know what it is.
And as far as I know, cheating is the key part of it. But if MC rejects girls or picks a GF, it simply can't be NTR at that point.
So the whole thing about DPC loosing fanbase over it seems unrelated to NTR, more so showcase of people not willing to see anyone else enjoying life and the LI's you rejected. Pure incel behavior: If I won't have her, no one ever will, hurr durr.
If I'm wrong about my understanding of NTR, freely correct me.