I assume during late night Talk shows (John Batchelor and Red Eye Radio) the Westwood One news airs at the top of the hour on WYAY, since both shows break for about eight minutes at :58. It really is an odd-sounding newscast, very fast-paced, with opt-outs at :01, :02, a spot ending at :03, another minute of news ending at :04 and another spot ending at :05. At :01, :02 and :04, the newscaster simply says his name as the outcue. No network mentioned. Cumulus flagship WABC New York only runs it late night, during Batchelor and Red Eye, since WABC has local anchors during the day. I've heard WABC sometimes take only the first two minutes, other times taking the full newscast.
As for other Atlanta stations and their network affiliations, as mentioned above, WSB has CBS News, although I'm not sure if they air the actual newscast at the top of the hour, even overnight. 1380 WAOK is a Black Talk station owned by CBS, although again, I'm not sure if they air the CBS top of the hour newscast either. Does 1160 WCFO run CBS News hourly?
I believe 640 WGST, owned by iHeart, airs Fox News, which is distributed by iHeart, in addition to 550 WGUN Gainesville using Fox. 920 WGKA, owned by Salem, airs SRN News at the top of the hour.
I'm not sure if there's any station in the Atlanta area or nearby that airs ABC News at the top of the hour. When all the Cumulus stations, including WYAY, went with their own Westwood One newscast on Jan. 1, I'm sure the ABC affiliate list plummeted severely.