When Fox 97 become Jamz in 2003, Cox used other stations from out of town as the stunt during the weekend. Don't know which stations were used. The stations changed every 30 minutes, with references to something "Peachy" and a WFOX legal ID in between.
Cox stations 95.5 the Beat and 97.1 The River citygrade Athens thanks to their transmitter location in Hall County (along with 104.7 The Fish and True Oldies 106.7). However, the other Atlanta stations do not. This is a good choice, considering Athens is the location of a major university.
As for Magic 102.1...B98.5 does not citygrade Athens. If Cox wanted to, they could turn 102.1 into a full power repeater of B98.5 (and WGAU a repeater of WSB-AM, and so forth). But it seems Cox thinks programming locally is a good idea. Remember...Clear Channel does operate their Newnan stations seperate from their Atlanta ones, even though they are close by (and in the same metro area).