Main thing I recall immediately after the assassination was that ALL radio stations stopped playing music for several days...something that would clearly not happen today under a similarly dreadful circumstance.
Au Contrare...many music stations stopped on 9/11/2001 and went all news...some even abandoned commercials. So I think something of the gravity of a Presidential assassination would. Agreed, not all would, but there are still a few companies here and there who have a conscience...
I remember on 9/11/01 that Z-93 & Hot 102.9 went to a CNN feed, while CC's Mix 107.7 & The X went to ABC NEWS. WBNS-FM/Columbus(Which had went Hot AC two months earlier as "The New 97.1) went to a CBS news feed. All of them stayed without music for most of the day IIRC.