If you turn off the music and select Captain Falcon on the character select screen, an extremely faint grunt obscured by the Announcer saying Captain Falcon's name can be heard. In the game's sound test, audio files can be found with "DEMO" attached at the end of them showing that every character in the game had similar planned sound effects on the character select screen, but only Captain Falcon's sound remains audible. Additionally, in the game's files, animations labeled "Select" and "SelectWait" can be found for every character in the game, many of which were either ripped directly from Super Smash Bros., are unfinished, or were repurposed in the final game. These are all presumably remnants of an earlier version of the character select screen that more closely resembled Super Smash Bros., where the character's in-game models were visible and used special animations and sound effects when selected.
Contributed by MehDeletingLater