No top-10 LHW or HW is fighting Cormier with 2 weeks notice.
This is a no-lose situation for Cummins: he's not expected to beat Cormier, yet he's now in the UFC's good graces by taking the fight on short notice, guaranteeing him at least one more fight there. And the added publicity he created by calling out Cormier puts more money in his pocket.
You can be the Alpha Male. I'm the Omega Male, the last man standing.