When I hear the ed 3 of Inuyasha the Final Act or the ed of Detective Conan Movie 07: Crossroad in the Ancient Capital, it always makes me picture a scene of a spot almost fully covered by fallen and falling cherry blossoms. (Especially 1:08~1:20 in the ed of Conan.)
I checked out the original MVs in the anime, and the scenes in the eds do contain cherry blossoms. Besides, stories in both anime have something to do with cherry blossom, too. Therefore, it's quite safe to say that the producers meant to use the music to create an atmosphere of cherry blossom.
I'm not sure whether that's only my personal feeling or a common feeling. However, neither did I know the origin of the music nor watched the MV the first time I listened to these two pieces of music, so it's probably common among quite a few audiences to picture a cherry blossom scene. I think that there might be some rules or theories (used by anime producers) on how certain melody/instrument/voice arouses certain feeling.