Yes.
Despite the fact that Trainz will load and use the latest version, the route will still show missing content if the EXACT version called in the route config is not installed.
This is a crazy oversight and needs fixed, but until it is you have the choice of either cluttering your system with a zillion obsolete assets Trainz never actually uses -or- live with lots of routes showing missing content when in fact you have the up-to-datest version of everything...
Andy