The mythological name of Eris was assigned to (136199) 2003 UB313 because its discovery created a great debate between astronomers about "planet" definition.
The discovery of (15760) 1992 QB1 [Albion] proved the existence of Kuiper Belt and brought on the disagreement of Pluto as a planet by some astronomers. Almost ten years later, the discovery of (136199) 2003 UB313 (Eris) made crucial the debate, and less than a month after the IAU resolution about planet definition, they decided to give the name 'Eris' to (136199) 2003 UB313 because of the debate than brought on its discovery.
That is a meaningful synchronous event recognized by astronomers.
