Have a SYD-CPT-SYD coming up in J and on one sector the seat map is showing old F Class and upper/lower deck J class for selection(of course I grabbed 1A and 1K)

I was under the impression that F became J and J became Y+, or am I mistaken?

Does QF block old F class selection to non/low status pax as I note there are still seats in the F section available while a lot of J is also taken?

CJ