As regards to tomorrows sale, are the tickets that are showing now the only ones that are going to be available?
If it follows past form, restricted and severely restricted view seats will be released when availability drops to "Poor". At that point, you will see the availability rating go back up a category for a minute or two before dropping back to "Poor".
When it goes to "Sold Out", odd seats will still keep appearing as people release them from baskets, sessions time out and payments fail.
After this week's sales, there will be still be the allocations kept back for local and general sales. There will also be tickets from members who return them for a refund up to 14 days before the game, unwanted staff/players tickets, possible returns from the away club, and unsold/returned hospitality tickets.
Bearing all of that in mind, I've seen no evidence that any seats are held back for the next sale, apart from the restricted views.