In 2006, IAU changed its rules on what constitutes a planet. The most famous downstream impact of the new rules was that Pluto is now classified as Dwarf Planet (Plutoid) among Trans-Neptunial objects; and not as a planet as before.
Wiki list of popular culture impact doesn't mention any SciFi works that treat Pluto as a non-planet so far.
What was the first >=2006 SciFi work that explicitly referred to Pluto as NOT being a planet?
NOTE: Doesn't have to be a major plot point. Just the fact that the text/movie clearly states that Pluto is something other than a planet, in any context