While I don't particularly endorse people harassing "insiders" for uncontrolled hype, I do think people are far too kind of leaker culture here.
These are leakers people. There's a reason companies hire people just to manage community and social networking, and it's because you need to be very controlled and careful around how you interact with fans.
If some rando decides that they would rather have all the attention and glory and start leaking stuff, it's on them when those fans turn rabid on them and start calling for their head. THIS IS WHY YOU DON'T LEAK STUFF. Well, one reason of many.
Sure, let's call for human decency and for people to control their expectations, but I'm not going to sit here and pretend leakers aren't the cause of their own demise.
Gooigi's Mansion released last year, you don't get to compare this to the Wii U
Seriously though Nintendo's having a trash 2020 but to compare it to the Wii U is ridiculous, not only did we still get some pretty high-tier games in AC and Xenoblade, but also the sheer amount of high profile exclusives from third parties that have been announced is something that would never have happened on Wii U.
While I somewhat agree with this, I would counter that three years into the Wii U the stuff we got first party included the likes of Splatoon, Mario Maker, Xenoblade Chronicles X, and Yoshi's Woolly World. Sure, we also got a lot of stinkers (ew Mario Tennis: Ultra Smash and Amiibo Festival), but those other titles were phenomenal at worst.
This year you mention AC and Xenoblade, but one of those is a remake of a ten-year old game. And, hot take, the content in this AC pales in comparison to previous installments due to the desire to pace out seasonal releases, so it's still kind of a slow burn title with a slow drip of RNG-fueled content. Also it was supposed to be a 2019, just got pushed to 2020.
So yea, this is a terrible year for first-party Nintendo.