What does "less exclusive" mean here? I am not sure what you mean from the context. People who tend to travel in F tend to book last minute rather than having things locked in a T-11months, like the careful mileage planner would have to do, so it seems unlikely that you meant that the cabin is "less empty".
Why do you think the later bookers are getting it for a "much lower cost"?
As you seem to be rather new to AF, you may not be aware of the bugbear that was the friends and family travelling for free in La Premiere for a long time, most of which seems to have now come to an end.