Tule Springs could be downgraded to unclassified since right now it is technically a dead-end road, though considering it is actively being expanded—the rest of it under construction right now—I wouldn't overthink it. Summerlin West currently has a lot of roads in this situation right now as well.

Theme Road on the other hand is a rare case of an un-extendable tertiary stub. It's a lengthy, busy collector road, but it has no outlet. Stubs of any classification can exist in rare cases if the road is significant enough, and usually they're caused by geographical restrictions (like the road is within an island, peninsula, or valley) or because the development has ended and thus so has the major section of the route (see southern Pahrump, Sandy Valley, and Mt Charleston for examples of tertiary/secondary stubs). The Sparks/Spanish Springs area has a few tertiary, secondary, and primary stubs as well.