Even though they are legally known as WCFS, 105.9 FM has been simulcasting WBBM 780 AM's all news format since 2011. The only time WCFS is even mentioned is at the top of every hour when stations everywhere identify themselves, regardless of format.

I don't know if Audacy, WBBM/WCFS' current owner, bothered to change the call letters when 105.9 FM
dropped its "Fresh FM" adult contemporary format from a branding standpoint.

Something else I have noticed. Audacy's family of stations have been airing commercials on CHSN. I don't know if it has to do with the RSN simulcasting 2 hours of 670 AM The SCORE's "Mully & Haugh" in exchange for cross promotion of the 7 Chicago stations Audacy owns.

If you are lucky (or unlucky) to have CHSN like I have, it's something I have noticed.