So on my prototype Union Pacific Coast Division (SP Coast Division) there are no wye's or reverse loops for a very long way... accept for 2 military installations along the mainline. Vandenberg Air Force Base has a wye that appears to be functional still, and Camp Roberts which is a big international friendly forces training center has a loop around the back of its flatbed loading yard that is most likely operational. Would Union Pacific have any access to those for its own commercial needs? Would they want access for logistical use to reverse locomotives along this line? Would local short lines, Santa Maria Valley Railroad and the white hills extension and ore facility that has a road switcher be able to use those military facilities to turn a locomotive around? If military tracks are used by the railroads for logistical reasons related to other freight or passenger trains than those directly contracted to transport military cargo, then I would include that logistical functionality on my layout and have a wye or loop, if not, then I would leave them out as there is no ability to do that on the prototype.