> Do something, so we can change it

This is what musicians do - put in nonsensical filler lyrics until they work out the rest of the song. Sometimes the throwaway lyrics are even kept. The Beatles did this to great effect in the Get Back documentary. It was so cool to see how the now legendary songs took shape. You got to start somewhere. Everything is iterative.

Video games are like that too, just put in default models, textures, placeholder music, and iterate until it's done. Mind you, some placeholders have copyright protection, IIRC a game shipped recently with copyrighted music that was used as a placeholder.