Each nameplate is named after famous people, places, and events.
If the locomotive's don't have a nameplate they don't work for the public and that's why no locomotive was ready for public appearance without a nameplate.
In a couple of years the names of the nameplate needs to sometimes changed or they can sometimes like to leave it the way it was used to be named.
On steam locomotive they mostly have nameplates and they are the only ones that have nameplates and on a couple of them they don't need nameplates instead the names can be on the cab window, or on the tender.
On diesel locomotives and electric locomotives they sometimes do or don't have nameplates.