The VI execution system has to handle lots of calls to subVIs that run for nanoseconds, so it can't afford the overhead of recording when it is actually running (at least, that is my understanding). So not really a bug. Though, it would be a good idea to that enum item from "running" to "reserved for running", to avoid confusion.
Personally, I use Queues created inside the dynamically-called VI to monitor whether it is still running or not, as references like Queues are automatically destroyed when a VI execution hierarchy stops running.
