I think this argument is lacking cause and effect. Sure, their ratings may be higher now, but back when they played pre 1964 music, they also had a lot more competition.
For example, there was always either WNJO in Jersey, or Sunny, or Solid Gold 102, or WFIL, or WPEN, or Oldies 1210, or Kiss 100, or EAZY 101, or WPGR, or Magic (when it was easy listening), or Jammin' 95.7, or Smooth Jazz 106.1, there were probably others too. (The new smooth jazz is no competition because it's not really smooth jazz anymore)
The point is they always had some form of competition. Now there is almost nothing. The B doesn't count...different audience, more hardcore than the WOGL audience. Even 106.1 is no competition because their audience consists mostly of women of a certain age.
Go to South Jersey and walk into public places such as stores and restaurants. Many of them are listening to WVLT, almost none of them are listening to WOGL from what I hear. I submit that if 98.1 started playing the pre 1964 music again that their ratings wouldn't be affected much at all because for many people there is nothing else to listen to anymore.