Yeah, they already leaked 5 years ago too.
Frankly, I'm not tempted to trust leaks given that not one of them mentioned a single detail about the new Mario Kart, when 24-person races and DK's redesign would've been immediate and interesting changes that would make people curious. It's also interesting that none of them ever mentioned the change in joy-con attachment, the new kickstand, or anything of the sort. Hell, the one "super confirmed" leak we got from that French guy a few pages back had some weird joycon grip thing in the back that was nowhere to be seen in the teaser trailer.
I truly think that being so confident about anything derived from leaks when we're this far out from learning the most basic details about the thing in official terms is dumb. There is every chance that what you stated to be 200% not happening will, in fact, happen.