To produce GPUs in mass quantities, AMD should have facilities. Production plants. I doubt they have large capacity ones, perhaps small pilot ones, or they outsource initial production to their tier1 partners, perhaps Saphire.
Their general policy was to make a crappy reference, ugly and with bad cooling, not because they didn't know how - but rather to limit "AMD Original" number of cards, and quickly switch the production, testing, logistic and so on - to the AIBs. They (AIBs) charge money for that, after all...
In 6xxx case, I don't think "they've learned their lesson", but rather did a better reference models because one of the chief NVIDIA trumps was that fancy 150g cooler - AMD probably wanted something that can't be directly characterized as crappy-cooling, appearing among "cons" in each review - stuff like that.
I'm not 100% sure about manufacturing capabilities, but the policy on not competing with own AIBs was always true for AMD, also for NVIDIA until they pulled that FE trick (which made AIBs thrilled)...