Gin betraying Aizen was as predictable as the sun rising. As predictable as Kane incapacitating Undertaker. It probably won't work, Aizen might beat him down, and we get another flashback about Gin.
Aizen will beat him down only to "lose" to Gin when he has to fight this new "more powerful" Ichigo... Though the start of the show suggested that he'd never get a "power jump", just be able to control his power... But hey, clearly Kubo isn't an intelligent mangka.