Advance purchase rules question...

A question borne out of curiosity more than anything else... I had heard that to get the cheaper fare buckets in each class, you needed to book some way ahead (21/28 days?). However I notice that my VS400 to DXB this Thursday still has N class availability on the VA site...
Is this just another case of 'we make the rules so we can break them' from Virgin - presumably in this case because they still have shed loads of Y availability on the flight? I'm certainly not complaining - as I have no expectations of being able to score an upgrade, a half empty Y cabin would suit me nicely!
RC
Is this just another case of 'we make the rules so we can break them' from Virgin - presumably in this case because they still have shed loads of Y availability on the flight? I'm certainly not complaining - as I have no expectations of being able to score an upgrade, a half empty Y cabin would suit me nicely!
RC