With regards to Blizzard not always giving clear or consistent answers to questions about the lore, and sometimes even outright lying, I agree that in the vast majority of cases it's justifiable to be pissed off at them in return.
However, sometimes story writers will lie for a reason that's also somewhat justified and isn't just "Well...uh...I dunno what I'm talking about, so here's this nonsense..." Most commonly, this is done to avoid releasing major spoilers that would be almost completely impossible to avoid without saying something untrue in its place.
What if every time George R.R. Martin got asked about the next Song of Ice & Fire book, he just gave a completely honest and straightforward answer of every part of the story contained within that he'd written so far?
It's the reason that people b!tch and moan, be it genuine or for the sake of some weird ironic humor, about all those datamined broadcast texts on Beta or the PTR. Hell, even Blizzard has referenced that factor multiple times now!
Giving away crucial plot details immediately upon being asked about them, just so that people trying to put the pieces together within the current lore don't have a brain aneurysm, can lead to inadvertently spoiling aspects of the story that will explain exactly what the f*ck is happening later on.
Now, am I saying that such a tactic is Blizzard's "motivation" for making this thread's topic so convoluted and messy for anyone to discuss in our specific circumstances, or even that they do such a thing often enough to warrant taking their supposed ignorance about their own plotlines with a grain of salt?
No, of course I'm not, as I and many others here are well aware that such a case is very improbable. Their recent track-record ("recent" meaning the last 5 years) has shown plenty of evidence that they probably don't even have the mental capacity to pull that off.
Yet despite my acknowledgement of that, in addition to the fact that I'm actually one of the many people who'd probably be super pissed off if this revelation were made under any circumstances, does it not at least seem worthwhile to speculate that Blizzard is both simultaneously moronic and "smart" enough to save the big twist of Sylvanas fully canonically mind-controlling her servants until the end of the expansion?