To be fair, I'm not sure I've seen anyone currently posting in this thread calling for LKD's head. I know that I didn't think ill of her for having incorrect details.
Oh, I know. I think she's been gradually redeemed, just the fallout immediately after the launch event was brutal. My opinion is the same now as it was then - she had valid info and info that was shakier, and just needed to do a better job at scrutinizing the latter rumours and being more transparent, rather than reporting everything with no additional context.
I'm assuming much like she though Splatoon 2 was a port, she or her sources may have thought Xenoblade 2 was a Xenoblade X port. A lot of the release dates are wrong, but this only leaves Smash Port, Mario Maker Port, Pikmin 4, Pokemon Stars, and Beyond Good and Evil 2 to be confirmed, and three of those have been heavily rumored by other sources, as well.
She
did clarify that her Nintendo source told her Xenoblade X port was not being done by Monolith, and that they were working on something else, which evidently was Xenoblade 2.
Regarding the release date slipups it also seems like plans just changed. Tons of people reported internal debate within Nintendo regarding whether Zelda or Mario should be at launch, and Koizumi himself even admitted Mario is practically done. Smash Bros. may have been intended for launch (as Serkan Toto said back when it was first reported) but strategically delayed either to give more room for ARMS, or possibly because the scope of the project changed. Considering how cautious Nintendo has been regarding the Switch's games, and Kimishima's note that they wanted to give more time to ensure a strong game lineup, they probably had a lot of internal contingency plans in case something ever went wrong with one of their tentpole releases.
Likewise Splatoon probably could have been an issue of the sequel branding not being decided until much later, since that's something that threw off all of the leakers.