Would I be right in thinking that as a plane overbooks in one class, availability in other classes is reduced by the system automatically ?

I am booked in J on Thurs and availability is showing as Y9, W?, J7, and F8.

I was curious about my prospects for a Gold upgrade from J to F so was looking to see if I could work out the F load. With 14 seats on the plane and 8 available, this would suggest that 6 seats are taken. However looking at seat availability in F there are no seats taken at all (it is true that 4 in the front row are not available but I cannot think that there are 4 Golds who have each selected these seats).

It also seems extremely unlikely that 6 people would be booked in F with no advance seat allocation for any of them.

This leads me to conclude that the aircraft is overbooked in another class and they are simply starting to balance out the overall no. of free seats between the different clases.

Have I got this completely wrong ???