A tribulation where people still work at clothing stores and machine shops, attend board meetings, go to school and movie theaters, use their cell phones, etc., is no tribulation at all.
I think they have been doing this kind of thing for awhile, when they chose to focus on one part they skip the details of what leads up to it. Only back when we studied the Revelation book did they really try to make sure the timeline made sense. Most people don't care anymore, another big message at the convention was "don't worry about the details of paradise, just make sure you get there," how very convenient.