I've never seen or heard any details of the contract between WLW and WLWT, but I would be very surprised to look in it and find a a phrase like "700WLW and its individual personalities shall refuse to accept any and all free publicity unless it comes from WLWT. Further, 700WLW's employees shall avoid any and all topics, despite any value they may have for 700WLW's ratings, if such discussion may reflect unfavorably on WLWT or its air talent, or reflect favorably or call attention to the programming or employees of other TV stations in the Cincinnati DMA."
If you've ever heard Bill Cunningham talking with an anonymous "private citizen" who sounds a lot like Tim Hedrick, or WLW's hosts and callers mockingly refer to stations other than Channel 5 using mathematical equations, (a reference to restrictions put on WLW when they had a deal with and were co-owned with WKRC-TV), you can tell they're not on a very tight leash.
I guessing the contract probably is one where WLWT gives WLW a significant amount of money to expose their weather, news, and sports personalities on WLW through forecasts and plugs, and probably to carry a certain number of spots as well, and agrees not to position rival TV stations in a similar fashion.