If WINS and WCBS had equal signals on AM or FM, only one would be all-news. You had that situation in Chicago when CBS had two all-news outlets, WMAQ and WBBM, both 50 kW non-D AM blasters. CBS had ownership issues in Chicago, so they chose to blow up WMAQ and replace it with all-sports WSCR.
I think it's possible that both WINS and WCBS could end up on FM. WCBS becomes an all-news simulcast (like WBBM and KCBS), while WINS goes with a news-intensive talk format. With equal signals on FM, WINS would no longer be superserving NYC. If that's ends up being the case, CBS isn't going to run two all-news outlets. WINS isn't going to 660. That's going to become the flagship of CBS Sports Radio.
WXRK (92.3 NOW-FM) has long underperformed against Z100 and WWFS (Fresh 102.7) is in a crowded field of stations serving female listeners.