A346 on VS1 / VS2 - why ?

I've just entered my API for a VS1 trip next week. Whilst in the "update booking" bit I had a look on the seat map to try and jockey a better seat - in Y as per policy.
Both the VS1 on Monday 11th Dec and the VS2 on 15th Dec show as a A346 - anyone any ideas why?
I would have thought with the $$ going through the floor there would be legions of people travelling before Christmas - so why put a smaller aircraft on?
Bad maintenance scheduling?
CB
Both the VS1 on Monday 11th Dec and the VS2 on 15th Dec show as a A346 - anyone any ideas why?
I would have thought with the $$ going through the floor there would be legions of people travelling before Christmas - so why put a smaller aircraft on?
Bad maintenance scheduling?
CB