Let's be realistic here.
If the entire purpose of Radio One's format swaps is to get the WBT news-talk audience on FM, then a major news event is exactly when they want 107.9 at front of mind. Putting that coverage back on 1110 after they've spent weeks making sure the existing audience knows to go to 107.9 would be entirely counterproductive.
And regardless of the extended reach of 1110 outside Charlotte, the only listeners Radio One can sell to advertisers are the ones IN the Charlotte market, all of which can get 107.9 just fine. Radio One doesn't care if you're listening to WBT in Spartanburg or Asheville or anywhere else.
If there's an EAS activation, it will run on 1110, but that's all that will run on 1110. There's no FCC requirement that any licensee do more than that for emergency coverage.