On Line Seat Selector

Hi, I'm travelling on the VS21 (Premium Economy) on September 21st. When i look at the on-line seat selector on the Virgin Atlantic website it is currently showing a A340-300.

My question is, if the aircraft changes to a A340-600 will the on-line seat selector be updated? At what point is it likely that the aicraft is definatley assigned?

Yep seat selector does change, I would think when the aircraft changes.Our trip to Bos showed j2000 747 400 from when the trip was booked in Feb until it changed to suite about 2 weeks before departure.