They might, but I feel like they pull new characters from their current staff. Like Anna and Elsa, for example, they never had auditions for them (but I hope they look for those two on Sunday!), but they did have a Merida audition a long time ago. So maybe they need to see if the people they have can pull it off first, then cast for more if needed.
Also, DLR added a character performer audition for the 26th!