It's common practice to do episode summaries of each episode. You could make the same argument about nearly every episode of every show that is also exhaustively chronicled in wikipedia. Why not add the tag to every episode of BSG, B5, Star Trek in all its incarnations, the Simpsons, etc etc etc? I'm reaching for why you're putting the tag on this particular episode rather than making this a general topic of conversation elsewhere, such as at the village pump. 

 I'm not reverting your tag, but I do think it is inappropriate.