Although I fully understand that this could very well be a Drakengard reference, i don't think that it being a reaction to Scalebound (either from Sony or PG themselves) is that far fetched and just for the sake of the argumentation, i will try to defend it.
Obviously there is the timing, it would very unluck if this was indeed a coincidence.
Then, you have the way the sentence seems to be about something recent. If it means to say Dragons are extinct, there were other ways.
Finally, Drakengard as a series managed to sell just over 1M over 10 years of life, half of that on Japan. Actually using a Drakengard reference in a serious prommotion material of its spin off game in Polony sounds at least as a very weak marketing push.
Scalebound cancellation is trending among game channels and because of that it can very well be more recognizable than Drakengard right now.
