Nothing against Mike, but I think it's possible (and normal) that after 6 years together he has nothing new to offer to her game I like that she's looking for a new direction, even if it will take time.
It's gonna be interesting what her new coach (do we have a nickname yet?) is gonna tell her in the tournaments where on-court coaching is allowed. "Be more aggressive"? "Just keep going"? "The girl will falter"? "Just do what you want"? Or actually something constructive?