Development also includes the pre-game phase; working on storyline, art sketching, etc.I would wager there is a long time of that, before things even begin to land in the game files.They probably started on this somewhere in BfA :)
Remember Blizzard's statement about the next 2 expansions always already being in development at any given time? (This doesn't mean Alpha, but that they've already laid out the blueprints and decided the main lines upon what's to come next couple of years.) Meaning that right now they've already been working for like a year on 11.0 and that next year they'll start working on 12.0 as well.
Seems like work on a new xpac started long before any offical date given. If any thing we are going to hear about how so and so had the idea and just started rolling the idea of DF around.
That's not true. Development starts much earlier. If you followed Bellular's podcasts you'd know.
you're only accounting for when you see that in the datamining not when they first start meetings, art and storyboarding, designing, early code that hasn't been pushed to any build thats just local etc.