Actually, the end of KFOG simply signals the end of AAA as a viable format. It is also on the decline in Portland, mostly due to aging. Same in Chicago with WXRT. It is very much alive in Denver, but that station has a very strong community heritage going back to the late 70's when Bob Greenlee opperated it and had Dennis Constantine as PD.
But elsewhere, AAA is pretty much an aged out non-viable format.
MOR aged out. Beautiful Music aged out. Smooth Jazz aged out. Standards aged out. Oldies aged out. The formats ceased to be commercially viable. While each format may have had passionate listeners towards the end, advertisers had no interest in reaching them.
Adjusting to reality is part of radio's century worth of resilience. Dropping a format that was no longer viable and replacing it with one that is alive is just part of the cycle of change.
Dropping a no longer viable format is not a death spiral; it is a demonstration of agility in a changing media environment.
And adjusting to the reality of sharing listeners with new media... or even better, making new media offerings... is part of that same resilience.
I'm not sure where Denver stands but KINK has been AAA since 1976, when it evolved from Progressive="Rock, Folk, Blues, Jazz", beginning in 1968.