I've been thinking about this, and it seems to me that the concept of bitGold and bitSilver would have entered our consciousness at the same time as bitUSD which stole the stage (these would have both been introduced in the august 2013 whitepaper).
People probably were talking about bitUSD since before november.
Since the possibility for bitUSD to exist also implies the possibility of bitGOLD existing, so all the discussion in 2013 about bitUSD would have applied equally as well to bitGOLD, so those should be considered a part of its history. bitGOLD just didn't enter people's consciousness until they realized in november that it was a natural extension of market pegging.
when I get time, I'll comb through a search for "bitUSD" to see if I can find any relevant discussion.