TV shows have established in the past that the televersions of celebrities are related to the fictional characters of the TV Universe.
Megan Russert of 'Homicide: Life On The Street' and Tim Russert of NBC News are related. Vera Louise Gorman of 'Alice' and Art Carney were distantly related cousins.
And the same kind of thing has happened in the Tooniverse.
Hank Hill, the main character of 'King Of The Hill', is cousins with bass player Dusty Hill of the group ZZTop.
It's never come up before on the series because Hank has always tried to protect his family from the shallow but enticing world of show business.
Maybe someday we'll find out the Griffins of 'Family Guy' are related to Kathy Griffin (if we haven't already). And based on recent news events, perhaps we'll see that Peter Griffin was ultimately responsible for smashing up the car of his "black sheep" cousin Eddie......