Is Boo the Only New Playable Character in Island Tour?

The long awaited opening of the official site for Mario Party: Island Tour has revealed the list of playable characters in the game:

• Mario
• Luigi
• Peach
• Toad
• Daisy
• Wario
• Waluigi
• Yoshi
• Boo

Although unlockable characters have not been confirmed or denied, the site gives no indication of any other characters. Do you think this is the final roster? Share your thoughts in the comments below!