For NBC radio, if it is any consolation Jack Welch later said his biggest mistake as GE CEO was getting out of the radio business. GE missed the whole wave of deals in the '90's and had the resources to profit from it. Also they blew it with Howard Stern. Like him or not if they had kept him at WNBC and if they had done the syndication that would have been kept NBC radio relevant for at least a couple more decades.
With Disney I've wondered if they knew the writing was on the wall for many of their stations and didn't want to make the investment to rejuvinate them. Many of their historically successful properties like WABC, WLS and WJR were all circling the drain in short order after being sold. It didn't look like the new owners did any big changes to break them just did not have resources to refresh old fading programming.
I totally agree on the CBS piece and think they are making a mistake long term especially with their News/Talk/Sports stations. Maybe radio won't be delivered by radio as we know it in the future but audio streaming will still find people that want news, sports and talk. They have that in a much more entrenched way than many other radio groups and people do seek it out. Top 40 I can get anywhere and it is pretty much the same. I don't need Kiss 108 when the same music can come from SiriusXM or Spotify but I can't get Dan Rea or local Boston news on Spotify. CBS is putting all their eggs in their NFL deal (guess what - ratings down on CBS-17% this year with a projected hit of 5% to earnings in upcoming earnings report) and on CBS All Access. One thing for CBS radio though is just keeping a limited number of news talk and sports stations is probably not that viable as sales is done at a cluster level selling all different demographics. A WBZ, WINS or KDKA is probably more profitable - at least for now with over the air radio - when sold along side sister stations that compliment them as part of an overall ad campaign. Going along with that I would think selling TV and radio ads together would be a good strategy but it seems like they don't do it that way.
SiriusXM proves people will pay for audio. Keep CBS radio and add it to CBS all access as another delivery method. Maybe add some exclusive audio content since it is subscription service. For example, make reruns of radio show available on demand, put the podcasts on there rather than as freebies on the main web site and for news or sports interviews not run in full over the air make the full versions a CBS all access product.
I have my own private prediction that long after FM music listening has gone online and local TV news fades even further in relevance that local radio news/talk will still thrive just because it can't be done in a national, consolidated way and is cheaper to do than TV. You sort of see that same thing with small town newspapers. I can't go online and find out what happened at the local school board meeting for my 20,000 person town because Drudge, Breibart and all the big news web sites don't care. It is still the local weekly or daily with pretty much a monopoly on that reporting.