There's probably a few indie stations still carrying 'worn to the plastic' Warner Bros. and Paramount cartoons in the public domain on old tapes complied by a station's programming department in the mid-80's. But even then most of the WB (not Hanna-Barbera), MGM and Paramount libraries are on YouTube, whether company uploaded or grey-market, so who wants to watch those with Bathfitter ads all over the place?
I know WITI in Milwaukee airs Rocky & Bullwinkle here and there in dead spots when the house flippers aren't in town gobbling every infomercial timeslot, and they even have RKO General-era colorized pictures early Sunday mornings. Outside of that though, unless it has an E/I logo in the corner, it ain't airing on a broadcast station. Even the Program Exchange, which distributes R&B and fills quite a few Sinclair stations with their product, is down solely to Jay Ward product animation-wise.