Do they release UC seats week before flight?

I am travelling to HK next week on the VS200 and when I wanted to request my favourite seat (2A) back in August, I discovered that all the seats at the front of the plane were already taken. Not really a problem and I decided to try out new territory in 9A. However, when logging on this week it seems that all 3 front rows in A , D and K are now available. Strange thing is that this is also the case on my return flight 5 days later.
Was just wondering whether Virgin block book certain seats for any reason - or is it just coincidence? Of course I have now requested 2A - though of course I know I could end up anywhere!

It might be that people had them booked on a J ticket and then cancelled thus freeing up the seats.

I have regularly pre-booked 2A on this flight and haven't noticed any blocked out seats although there are certain seats that usually go first. I think it may be as contactor suggested, they were J's that used their option to cancel.

[Darren Wheeler]

Or they booked via 3rd party such as Expedia and were automatically allocated those seats, then changed them.

Can anyone shine some light on why 2A is so good as I can't sem to see why in pictures? I have a flight on friday to SYD and A2 is free. Like the OP when I booked the flight none of the front seats were free, now they are.

The reasons I like it are as follows: nice and private; great to have a cupboard next door to the seat; very quiet with nobody walking past apart from crew; a long way from the bar (not everyone's idea of good, I know); not far from the toilet through the front cut-through; can be very quick getting off if the front exit is used on arrival. I've sat further back and enjoyed it less - seems just a bit quieter at the front. Everyone has their favourite seat I suppose!