I find it funny that this forum had multiple threads about information from supposed "insiders" like Emily Rogers and Laura Kate Dale all leading up to the Switch event where most of said information turned out completely false or absent.
It's once again someone on /v/ who has the accurate leaks.
Emily had the best track record IMO. Looking at the stuff on her blog:
https://arcadegirl64.wordpress.com/...-kart-for-switch-brings-a-mix-of-old-and-new/
Aside from the 16 new courses (which is possibly her source counting the DLC tracks as the new courses), everything else reported here (new battle mode, characters, first three months) is correct.
https://arcadegirl64.wordpress.com/...th-of-the-wild-will-not-be-released-in-march/
She initially thought Zelda might not be at launch. Upon checking with sources at NOA later, she changed her tune and believed that Zelda would indeed be launching in March. LKD's suggestion is that NOE was pushing for a delay due to EFIGS, but NOA and NOJ always targeted March and ended up winning out. So let's give this point to her.
https://arcadegirl64.wordpress.com/2016/09/02/rumor-what-should-we-expect-from-the-final-nx-product/
Pretty much everything she said about the Switch hardware was correct.
https://twitter.com/ArcadeGirl64/status/819440363903582208
Suggested one of the previously-reported Switch ports would not actually be a port, but Mario Kart would be. Splatoon was confirmed to be a sequel.
https://twitter.com/ArcadeGirl64/status/819360693677936640
Doubted Skyrim would be a launch game. This was true.
That's just from the past few weeks because I can't remember what else she said earlier.
The only points against her at the moment, off the top of my head, are the MIA Mother 3, no female player in Zelda, and the new courses in Mario Kart (which might have been her source interpreting the bundled DLC tracks as new courses). But she believes the former is still coming. The latter is looking unlikely at the moment but some people seem to be holding out for playable Zelda. I don't think she commented on the 4chan leak. Her conduct was also the most professional of all the leakers imo.
LKD got some stuff right and was misled by some sources. I think she might have just been a bit overzealous in some cases but a lot of her info was legit.