The interest/curiosity has been completely drummed up by the players. DPC showed a locked door and everybody's minds (at least here) went wild with theories about miscarriages, a KIA soldier husband, Bella being another Leah, sex dungeons, etc.
DPC hasn't really done anything to make this locked door seem like it's as big a deal as people here make it out to be, so if it turns out be nothing much, then they haven't undermined anything.
This is what you call a "red herring". The TV series "24" did it all the time, in every season, where the first major villain/crisis was never the main one. You knew to expect it but it didn't diminish or negatively impact that show in any way so I don't see this being such a bad thing if it turns out to be nothing major.