Yes, I have the read the blue post, and it does not state at any point that spell-batching of this nature was something they intended in 2004 and that they balanced around it. Only that they have scaled back how, and how often the server processes the batches in classic to have a more 2004 feel. The fact that they stated:
Makes it sounds like this was more of a technical limitation on the hardware of 2004 and since with computers and servers becoming more powerful and faster they have been able to tighten this up to the point where we are players have almost no clue its still there on the backend and not a design decision that they balanced around. Since to me, this reads more of code/process refactoring and not a change in design/balance philosophy.
Again though I would love for the Devs to confirm this and go deeper into how the batching system currently works and how it is different/the same as it was in 2004.