By this logic, lets just avoid giving any info on worlds altogether, because any statement from WotC might cause confusion. Don't fool yourself, when someone reads an official D&D product and gains info from it, they're going to assume that it's the default, i.e. canon, not some random inspiration for DMs to write an adventure. So, each and every bit of info about a world would lead to the "confusion" that you mention. I mean, players who have some knowledge about that world might expect certain things to be true and certain others to be false, and that would be "confusing" by your logic. You know what? Lets just stop making assumptions about basic D&D concepts like races, because players might expect something from certain races, and DMs might want to do something else instead.
Or maybe, the DM could just state at the beginning of the campaign that they're just borrowing some elements from a setting, rather than 100% adhering to it...
Detailed worlds aren't confusing, they're indeed more immersive than bare-bones settings.
Canon may be irrelevant at certain tables (like mine, btw) but it's needed by game designers to provide a coherent portrayal of a certain world, and WotC do have their own world bibles and canon. So there's a canon, a default assumption, and that's the info that you read in their books. Every designer needs to be on the same page for extremely obvious reasons: anything else and you get a bunch of random contradicting info, rather than an organic and coherent presentation (and the internet already provides plenty of adventure ideas without the need to pay for anything).
Brilliantly put, a lot better then I could have honestly.