I bet next season Kirk is assigned to the Enterprise on temporary assignment. Eventually he selected over Una to replace Pike when he is made Fleet Captain. We know she won't be kicked out of Starfleet so it might be something like how she wants to go teach at the Academy or something.
2265--
Una: The Enterprise should be mine! I'm the first officer and now that Chris is getting promoted I'm the logical choice to be captain.
Kirk: Ahem. Go ahead and do that then. If you really want the most famous ship in the fleet to be commanded by an... augment.
Una: Why you no-good, stuck-up, Iowan farm...
(Admiral April turns pale permanently from embarassment, but ultimately gives the Enterprise to Kirk)