Let me make that a little clearer...

The employee site shows 2 numbers for seats available based on bookings - X in FC and Y in coach (assuming a 2 class aircraft). Not specific seats, just the number of open seats based on bookings. Those that book coach (seat assignment or not) but are eligible for upgrades - elites and Y/B coach fare - are used to calculate the coach "seats available" until they upgrade, at which point they change the FC and coach "seats available" - decreasing the former and increasing the latter.

Your particular flight, when I checked, showed 7 FC seats available (with 9 installed it means 2 taken) and 0 coach available (booked full or oversold). Anyone upgrading after I checked would change those numbers - reducing FC seats available and increasing coach seats available (unless the flight is overbooked).

So seat assignment doesn't play a role - nowhere does it say which seats are assigned, only how many are not booked. For the employee site, upgrades are treated as being rebooked from coach to FC.

Jim