Afaik, the United pilot group isn’t in mediation. Assuming that’s true, there’s zero possibility they could “move to strike,” because there’s no chance the NMB would release them from mediation (which is a requirement under the RLA to eventually strike) to a cooling-off period because they aren’t even in mediation right now. Once they’re in mediation, they’d have to be in mediation for a minimum of two or three years before the NMB might consider releasing them.