A lot of concept art ends up being released after the movie goes to the cinema. Or that the series ends and Moon Knight is an example. Konshu's concept art is revealed to everyone and again shows the character darker than the one we've seen.
Alternative Moon Knight Skins were released and covered here on Coliseu Geek! Ammit had concept art revealed also recently! I really like seeing these arts because it helps even more to understand how they decided to bring the characters to us!