I think the reason for the move was simply that maintaining the separate site at Cantonment made no sense to the CC suits back in SA, when they could just slap it on the Baldwin stick.
The downgrade from a C to a C-0 undoubtedly relates to short-spacing with existing sticks in Lucedale at 106.9--just an A, but just west of Mobile--and the full C at 107.9 north of Biloxi. Can't just move a full Class C FM 15 or 16 miles without bumping into something else, these days.
And, frankly, on paper it looks like it should work, doesn't it? Trouble is, people don't listen to radio on paper.
Still, I think CC will stick with CHR on 107.3 longer than most of us think. It covers some demo holes in the portfolio, and gives them a chance to steal some bucks from both Cumulus & WABB.