From what I understand, after the "CBS4" edict, there were ongoing discussions back and forth with corporate, with the local management making the case on the value of, and why they should retain the WBZ branding. Eventually corporate folks acceded.
Wimmmex, I appreciate both your and kemosabe's backing up the disparity between CBS Corporate and local TV station management regarding the branding of the legendary Westinghouse stations.
In my reply to CTListener, I cited the exact article in The Boston Globe from whence my information came.