d1940 this is a perennial.
This is my understanding ...
AFL controls the seating for finals at Subiaco, so your reserved seating will be but a blissful memory of the H&A season. They embargo the best seats (usually along the northern side level 1) for their sponsors, the participating clubs (that doesn't include us season ticket holders), special guests, prize winners etc.
And yes, the seats that are normally 'less than premium' are bumped up and sold to the participating clubs' members as 'premium'. I remembered the PF in 2013, we were sandwiched in on L2 of the three tier stand. We got very intimate with everyone around (not by choice, I hasten to add).
My niece, not being a member, went to Ticketmaster on the Thursday before the game and got prime seating in a block like 150, once they released the 'untaken' AFL allocation.
Besides all this ......Lets assume your wish was fulfilled and you could sit in your H&A seat. If Freo was to play WCE at Subi (heaven forbid), how would you and some feral budgie person work out which of you had dibs on the seat? You could even get infected if you had to sit next to a supporter of the opposing team.