This isn't a big move or a great shock... it's just the way it's literally always been.
They aren't saying "none of that other stuff happened!"
They are saying, as they've ALWAYS said, that the evemts of your realm and game may differ from the events of the same realm as it appears in other people's stories, games, adventures, video games and novels.
The rough timeline for all of the events of past editions and how they form a coherent evolving world through different changes to the game are all still there and all still 'more or less' happened. The exact details are not specifically fixed because the realm is flexible enough for individual DMs to make individual worlds at their individual tables. That's all.
So, the historical events of the realm prior to ~1480 DR all still happened. Their precise and exact details are NOT defined, and even their exact outcomes are not precisely defined either (was this tyrant defeated by a band of adventurers; what were their names? Not defined. Was this nation saved from a dastardly blight by the valiant actions of heroes, or did the sinister lich actually get his way? Not defined. That those events occurred is a more-or-less element of the history, but the details and outcomes, less so). In that sense there is no precise and specific hard canon, and there literally never has been.
None of this is news. That doesn't mean that media that uses it should just throw it all out the window as "Lol, non-canon" and do whatever they like with the IP - that's not what is being said here.
Last edited by Niara; 04/08/21 06:40 AM.