Every commercial or teaser shown on the television as Rick and Morty watch other dimensional television programs was improvised for the episode's script. This is evident on several instances, including Gazorpazorpfield when he pauses for a moment, and when he laughs after the line is over ("Enchiladas").
Despite the advertised movie "Last Will and Testimeow: Weekend at Dead Cat Lady's House II" containing necrophilia, the text at the end of the commercial indicate that it's rated G for general audiences. However, as a show from another universe, it's quite possible that necrophilia is deemed more acceptable in its home dimension.
The idea of watching strange TV programs from other worlds/universes originated from House of Cosbys (2005), Episode #1.4 (2005), an episode of another animated series created by Justin Roiland.
Rick comments that the TV commercials have an improvisational feel to them which is an in joke base on the fact that that's exactly how they are recorded for Rick and Morty.
While many other episodes of the series takes place on strange and distant planets and in alternate universes, this episode plays entirely inside the family house.