It is going to be DC because.....DC is a favored-son of the UFC, Dana White loves DC, and so whatever DC wants for his last fight will be what DC gets. So....if Stipe stalls any longer then they'll strip him, and the onyl fight they're offering him is Cormier so either Stipe retires OR he is fighting Cormier.
The only thing that can wreck this is the damn virus. DC has commented heavily in last day or so that it is looking like him vs Stipe III around July. So....I just wanna see good fights. If the virus doesn't wreck it, let's get that on!
After that, the way I see it :
If DC wins :
then he retires immediately in the cage, nice speech in the Octagon, and ....the HW title is therefore vacated due to his retirement. Then UFC can make whoever they want for the vacant title and it's prob gonna be winner of Ngannou/Rozenstruik vs Stipe.
If Stipe wins :
then he'll *have* to face winner of Ngannou/Rozenstruik in his next title-defense.