Ah yes... in 2011. (it was missing on my shelf, so didn't remember it)

Although, in regards to that one, I remember that it wasn't something they planned ahead to do as a BotCon toy - it was more to do with demand from a concept image I think they showed the previous year (the Gen2-Actionmaster theme), and since Gen2 Ramjet (a seeker mould) was already planned as a Store exclusive in 2012, the AM Thundercracker probably had to be released at BotCon.
It inadvertently set a precedent though, but I think they've said on a few presentation panels, that they prefer not to re-use moulds (helps to separate each set as distinctly different).