According to the FCC website which has a section on tower registrations, I don't see there is a tower at this location which is south, southwest of downtown Buford.
The application does not show that FAA approval has been provided. Simply that it is being requested.
Actually, originally, WYAY was a bit lower on the tower than then WFOX. But put a better signal into atlanta for two reasons - one was the mounting of the antenna which, even after optimizing it for better circularity had a lobe towards Atlanta; and the fact that 106.7 was away from the local Atlanta stations in frequency, and thus didn't suffer as much from intermod problems at the receiver. The end result was, Y did a better job of being received in Atlanta than Fox most places.
Now, as to moving 97.1 closer, I wonder if the site chosen is what was the original 106.7 (Wide 107) tower on Friendship Road. The tower it was on when Katz bought it from Jacobs and decided to make an Atlanta station out of it. It's on Friendship Road, just East of Buford. There existed at one time a Determination of No Hazard from the FCC to increase the tower height by 200 feet, which would at the time have preserved the full Class C status of the station. This upgrade was not done because it would have been frighteningly expensive at the time (Another story entirely), and Shamrock, who owned WFOX, decided that they would allow Katz as a tenant on the tall tower. Although it was about 5 miles farther from Atlanta, the height increase (1500' AGL roughly vs 1167' AGL roughly) meant that the contour over Atlanta fell in the same place. Thus 106.7 was colocated with 97.1, and the Friendship Road tower was vacated except for 2 - way tenants. It still stands, and has a number of tenants, none broadcasters. WLKQ would fit on it, and was offered the option at one point, but the family who owned it at the time (the Josephs) declined.