FWIW: At one point a few years back there was a rumor going around that the way HR chose applicants was for them to wait for X number of applications to be submitted at which point they would go thru and select who they wanted to interview and, possibly, who they may want to interview at a later time. This suggestion felt plausible as it explained the active vs inactive vs locked conditions people were experiencing. As best as I can recall from these threads, locked is a good thing.