I thought for a moment on reading this that he said it was satirical rather than satanic.
Michael Schiavo was infamously reported to have wondered out loud when the “bitch would die.” From reading what this says about the plot of the show, it sounds like by having Terry called all kinds of dirty names, it is poking mockery at Mr. Schiavo.
Michael Schiavo does appear briefly as a character in the skit, but aside from mistakenly identifying a TV as one of the medical machines (probably a reference to his refusal to allow a TV in Terri’s actual room) I don’t think he comes off as an object of mockery. McFarlane is much more interested in portraying Terri as brain-dead and the pro-life protesters as morons.