We can still beat UNC without Cooper and Maliq—we just have much less wiggle room in how we do it.
In Chapel Hill we were able to pivot strategies midway through the game because of the flexibility Maliq provides, combined with Cooper's transcendence. Without them, we still have the guys to shut down RJ Davis and make someone else beat us. Doing that will just involve taking more risks (not switching with Man-Man, some more aggressive hedges, daring guys like Withers to make shots), hence less wiggle room. But we can still execute the game plan to beat UNC better than a lot of the teams that have beaten UNC this year. If Lubin gets a double double and Withers and Trimble make a ton of 3s and we lose, so be it. But we can make it so that that has to happen for them to win even without Coop and Maliq.
Oh, and BTW, I have to imagine every one on the court wearing a Duke jersey will be plenty stoked to get to put their stamp on the rivalry in said scenario.