Data point from me: My flight was £0 after redeeming a goodwill voucher, but my BAEC Gold card was most definitely not £0
On a more serious note, the staff in CX F were exceptionally good and coping well. I even noticed the lounge "matron" speaking to individual high profile customers, making sure they were ok. Furthermore, the restaurant staff were asking if people were happy to share tables in the dining area and respecting those who didn't.
I was sober, and didn't see people "spread out all over the place" and there were seats available in F throughout my whole stay there. Food was also always available, and the alcohol was topped up as soon as anyone asked for it. The only thing that did happen in J and then F was that they ran out of champagne flutes, but didn't hesitate to give wine glasses out instead.
Incidentally, most people moved to J on Saturday morning after about an hour, even those who were perfectly entitled to use CX F.