There's been rumors of a tenth anniversary concert. Gavin talks a little about it in his show people interview, but obviously Sutton would be playing Millie.
She'd be a fantastic Millie, but she'd also make a great Dorothy.
"Oh look at the time, three more intelligent plays just closed and THE ADDAMS FAMILY made another million dollars" -Jackie Hoffman, Broadway.com Audience Awards
I think she's more of a Dorothy, but I think she's been amazing in every role she's played thus far and I have absolute faith that she could be a great Millie as well. Even though GREASE and BONNIE AND CLYDE were bombs, she still gave 100% to the material. She was lovely in SOUTH PACIFIC and ANYTHING GOES.
As for a tenth anniversary concert, is it really necessary? If it happens, it'll obviously be great, but... does it really have to happen at all? Yet, at least.
To be clear, I wasn't accusing you of being untruthful, but if it is true it will diminish my opinion of her, so I'm choosing not to believe it. Accordingly, I am choosing not to click on the link you so graciously provided.
"It does me no injury for my neighbour to say there are 20 gods or no god. It neither picks my pocket, nor breaks my leg."
-- Thomas Jefferson
I don't think very highly of Throroughly Modern Millie. I would hope someone as talented as Laura Osnes would have to mention dozens of dream roles before mentioning Millie.
At the risk of agreeing with Seth Rudetsky, he often laments current Broadway stars' lack of appreciation for theater history. I think someone like Osnes saying that she loves the show and that Millia is a dream role would reinforce that opinion.
"It does me no injury for my neighbour to say there are 20 gods or no god. It neither picks my pocket, nor breaks my leg."
-- Thomas Jefferson
So what if Millie is one of her favorite shows? She never said it's the best show ever. I enjoy Wicked very much but know that it is no Gypsy. If it's one of her favorite shows and she is suited for the role then of coarse it's a dream role.
This interview was from her first year, while she was in Grease. Don't know how she would feel about it today. Just thought it is interesting that the OP came up with this idea that coincides with her own thinking during the interview.