User blog comment:IamJakuhoRaikoben/Chapter 463: Black Carpet, Review./@comment-1776824-20151123213644/@comment-7418318-20151124000455

That's the opposite of what Mavis just did.

She's not just letting FT sit there, but go along with the original plan, which is defeating Zeref's other forces and then take his main force in three-pronged attack from multiple sides with their full (surviving) forces.

To me that sounds that, despite her pretty words, she fully expects Natsu to fail. But Natsu failing won't lose the war. Natsu is just one person in this entire conflict and even without him, the original plan has good chances for success. Much better chances than what Natsu is trying right now.