Reckon Nike may have let her go at the end of this Olympic cycle. Pretty common. Maybe she could have renegotiated and gotten a reduction but likely wanted change. With a group like Bowerman I remember Fraser saying the logistics of her Nike vs. Bowerman deal were pretty unique. Essentially Nike and Bowerman is a package deal, and if you only sign Bowerman they can low-ball you, as opposed to signing with Nike, and then joining Bowerman. Reminds me of Tinman, where a lot of the group is "Tinman", not Adidas but subsequently gets adidas gear.
She raced in just random Nike gear at US cross, no Nike pro kit. Rachel is Hoka now and Elly is Adidas. Wonder where Emily will end up but I think she has some years left in her legs.