March 19 may be T-0. The countdown seems to point that way. But if true, that doesn't mean we have any clue what will happen at T-0. Q giving us a date (if true) doesn't imply Q telegraphing moves. (I agree that Q has been clear that we won't get that level of detail.)
We've had dates seem to slip past before without any evident big things happening, so I'm not viewing this as definite - just a heads up that there's a higher than ordinary chance of something unexpected and significant.
I'm reminded of Douglas Adams, where it was possible to either know the answer to the ultimate question of Life, the Universe and Everything (42) – OR to know what the question means – but not both, due to some kind of exclusion principle. (So we're left not knowing what the question means.) Similarly, maybe we can know either when something wll happen, or what will happen, but not both. (On the "not telegraph moves" principle)