because it has no meaning any longer - hell people today aren’t even listening to FM radio much less AM. They were smart enough to grab the iHeart Radio brand and build a good following around it, and it only makes sense to capitalize. After all, GTE was the largest independent phone company not that long ago, yet the name change to Verizon has only helped them grow faster and gain share.
Absolutely false. Channels are about talking and listening. How the people listen is a detail.
Clear Channel is a media outfit. Media is about communication. Communication takes place over channels! Obviously, a "clear" channel is a good channel! The notion of a channel is fundamental to communication, and thus to a media enterprise. Thus, dibs on the name "Clear Channel" is valuable.
Only radio nerds will know, much less care, about the legacy-tech FCC definition, LOL!