I have never heard the NBC and CBS rumor, but with the exception of the most of West Virginia, most of the class B’s are in areas that had cities that were in the top 20 or 30 population in the 1950 or 60’s and were within a 150 or so miles of another big city. An example New York, Boston, Philly, Washington Baltimore. Parts of California are “B” county too. With only 80 commercial channels, limiting antenna height and power was the only way to give these areas “local” stations. Example: most of the FM’s on the Empire State Building could not increase their power even if class C, C0, or C1 was allowed without wrecking the signal other stations serving cities with significant populations.By the Northeast, you mean East of the Mississippi River and North of the Ohio River correct?
I wonder why the FCC does not allow “tight” directional to solve on channel issues. 100.5 could go on the Fish (106.7) tower with 50 + KW with a super severe null towards WSSL. The FCC allows translators with funky patterns*
*W251CZ-FM Radio Station Coverage Map