Chinese airlines frequently fly with three pilots in the cockpit as did this accident flight. I have not seen anything which states how many of the three pilots were in the cockpit at the time of the crash.

I did see that. With three up front, it would seem unlikely that two would leave but who knows.

After Germanwings the Europeans decided to copy our rules and never leave someone alone in the cockpit. Then about 6 months later, after the media spotlight was removed, they quietly went back to their old ways. Inexplicable.

they don’t do the 2 person flight deck anymore?

That's why I heard too.