When I had Time Warner (Warner Cable prior, Jones Intercable prior) they had their own headend at the Kenosha office. Everything was pulled in OTA from a set of antenna towers. I’d regulary see static, lightning static on the Chicago stations. In 2000, they consolidated everything into Milwaukee which is when the static stopped. At that time, most of the non major Chicago stations were pulled from the lineup, the rest went to a direct digital connection, likely from a satellite or uplink. Until they had such an option, WBBM was never carried here because there was no way to pull in a good signal. WHA in Madison was also piped in.
Since Comcast is the largest and longest running cable system in Chicago (Many as a result of buyouts) they’re probably the only one WYIN has a direct feed for.