No cable system around here that I'm aware of (other than receiving it on Direct TV or Dish) has ever offered Boomerang since it debuted around 2002. Not even on digital cable.
And you want to expand this to include OTA networks that have always been missing from cable lineups, some large cable systems in western Illinois that have never, ever carried anything from MyNetwork TV--or back in the UPN era--has been the current Comcast systems in Quincy, IL and Macomb, IL (the latter the home of Western Illinois University, which attracts a large percent of their student body from the Chicago area as do many other downstate Illinois colleges). Because of the limited OTA allotments and small market percentage, there has never been UPN or My affiliates offered OTA or on cable in those areas--not even attempts to offer one of the My or UPN affiliates from neighboring markets as Peoria, Springfield, the Quad Cities or St. Louis.
Then again, it wasn't until the digital era that the Quincy/Hannibal market has been able to obtain the full Big 4 network lineup OTA (plus PBS, CW and religious WTJR-16--but still no My although they're not missing much). For years KTVO-3 Kirksville, MO served as the de facto ABC affiliate for Quincy (plus Macomb has always received WQAD-8 from the Quad Cities on cable--and up until the early '90s or so WHOI-19 from Peoria had previously been offered on Macomb's cable). And Fox was originally cable-only in Quincy through NBC affiliate WGEM-10's local CGEM service (which has now grown into subchannel 10.2), while many cable systems in the Quincy market had to previously rely on receiving Fox from surrounding markets as the Quad Cities, Springfield or St. Louis (or rely on FoxNet back in the day).