Seattle may be the last top 15 market that still identifies their news/programming by the original calls, with the exception of KCPQ (Fox, known as Q13). KING are simply great calls, and KOMO and KIRO are easy to remember. But I doubt we will ever hear CBS7, or ABC4 in Seattle. (Watch someone switch next week!,.
Interesting though but in San Francisco the Fox O&O here KTVU call their newscasts with both the Call Letters and network branding at the same time as in (KTVU Fox 2News) its branding has been around since Fox took over the station from Cox television in 2014-2015.
And KPIX the CBS O&O in the Bay area is uses the KPIX 5 News brand.
That was mainly to generate ratings for their audiences. I know that PBS/NPR affiliate KQED referred to their news segments as KQED California Report and KQED Newsroom