I don't see what's so confusing. You put together what is called an RFP, "request for proposals", and you send out a press release that the ACC is requesting proposals to host their baseball tournament and you include a format for cities to respond and cite the criteria based upon which the responses will be judged. Cities, major conferences/trade shows, and companies do this sort of thing all the time. Usually, you bid a couple of years in advance. So right now, the conference should be looking at proposals for, say, 2023, to be decided and announced this summer. There's really nothing all that complicated about it.
The way these events are currently being awarded would be considered extremely shady and even illegal in almost any other enterprise, but I guess since it's sports and "driving distance" most people don't bat an eye, even though their team are among the fans that need to "drive" the furthest to see their team play. But if a city wants to build a new building, let's say a police precinct, the mayor can't just go to his biggest donor (usually a developer) and say, hey, sell the city some of your land and build us a building on it. No, the city has to put out an RFP outlining their requirement, listing the criteria on which they will make their ultimate decision on which proposal to select, and ask any and all qualified developers to issue a bid to the city to provide the land and build the police building. Why should these games be any different? If Durham or Charlotte still have the best bid, ok cool, so be it. But let other ACC cities have at least a chance at these events, and by doing so, you maximize revenue to the league and therefore back to the member schools.
It constantly amazes me to get such pushback to this basic concept of fairness and maximization of utility to the conference on a Miami Hurricanes message board. Guess I'm just crazy.