And DIRECTV does have wgn in a regular package for most everyone.
The superstation package Dish has are the full versions of those local channels complete with network programming. Despite them at one point using Superstation in their name, WGN America and WGN-TV Chicago, as well as TBS and WTBS Atlanta util 2007, haven't been simulcasts of eachother since the late 80s and are not part of the package.
In the late 80s with the influx of new independent stations across the country that carried syndicated programming that also aired on the superstations at the time (WPIX, WSBK, WOR-TV, WGN-TV, KWGN, KTLA and WTBS), new syndication exclusive rules went into effect for cable that allowed the local stations to blackout programming they had the rights to. WGN-TV, WTBS and the now WWOR-TV all launched alternate feeds with programming they had the national rights to. WGN-TV had the benefit of being owned by Tribune who at the time was also the syndicator of many of the shows they aired, while WTBS and TBS negotiated for national rights for most of their programming as outside of public affairs programming WTBS was always programmed with a national audience in mind, WWOR-TV and the national WOR feed on the other hand had a very different schedule since the station's ownership changed hands multiple times and nearly lost their license in the 80s so they had no real clout and mainly filled the schedule with programming that was no longer nationally syndicated. WGN's national feed initially carried The WB programming to give WB a national audience, while WOR, who eventually eliminated their national feed in the mid 90s, never carried the UPN's programming. Since the rules only applied to cable, satellite providers are allowed to keep the full versions of the other superstations. At the time C-Band was mainly a luxury for people who either wanted more channels than their 36+ channel cable system would give them, or was used as the primary television source for many rural areas that either lacked OTA reception or wasn't served by any local cable system. Dish, Primestar and USSB/DirecTV were several years away from launching and wouldn't provide LIL service for another decade because of other regulations. Dish picked up the Superstations, but for whatever reason DirecTV never carried them.
KTLA, WPIX, WSBK and KWGN vanished from national cable distribution outside of a few lingering regional cable systems that are now subject to blackout. For example until more local affiliates launched cable systems in the northeast continued to used WSBK and WPIX as their initial source of UPN and WB programming. Here in NEPA, Blue Ridge still has WPIX, however some syndicated shows are blacked out. There was some online post a few years ago on another site about WWOR's airing of The 700 Club being blacked out with the on screen message inserted by the cable company just citing "FCC regulations", of course everyone ran with it like it was some conspiracy, not realizing that the poster wasn't in the NYC DMA and it was just the syndex rules that forced the blackout, so he could have seen it on one of his in market stations.
Canada is another story where the CRTC regulates everything so the broadcast stations were licensed and not the cable versions. They still get WGN-TV Chicago and when TBS and WTBS split, Canada got Peachtree TV while TBS's original programming like Conan and their MLB coverage is split between Sportsnet, CTV, The Comedy Network and Much.