Family Guy was cancelled once, which can sometimes be difficult to recall, even though it is about to air its 20th series on American TV. In another universe, Seth MacFarlane's animated sitcom, which was a huge success, was canceled by Fox in 2002 after its third season. Instead, it languishes in the memories of those who use message boards to swear they must go back to see the baby.
This alternate universe is presumably one in which Adult Swim doesn't exist. The Cartoon Network, an adjacent cable network, began airing Family Guy Reruns in 2003. They quickly rose to the top of the network's most-watched shows by a comfortable margin. Airing later, and in an environment more in-tune with the shows not-quite-primetime-in-2003 sensibilities, the show flourished, developing, alongside those mammoth DVD sales, the loyal fanbase that convinced Fox to give the series another shot, bringing it back in 2005. Family Guy reruns were a regular part of Adult Swim's lineup up until today when the last Family Guy rerun is set to air.
Thats because FXX (which, like Family Guy itself, is now owned by Disney, unlike the WarnerMedia-controlled Adult Swim) has just announced a major deal to secure the entirety of the shows back catalogue, as part of an effort to cement itself as the exclusive cable spot for all the animated sitcoms you used to love on Fox, notably Bobs Burgers, King Of The Hill, and The Simpsons. The Cleveland Show will also be present. Futurama and Oh, My God, will be there in November. American Dad appears to have continued to air on [as] while he is tied up with TBS. This means that Adult Swim's tonight's Family Guy reruns will be the last Family Guy episodes to air. It's the end of an era.