Why is Kirby in this Fortnite Party Royale trailer?

The announcement trailer for Fortnite's new Party Royale mode contains a small and inexplicable appearance from Kirby. 

Yes, that Kirby - the pink ball that eats everything and wears cute little red moccasins. The Kirby created and owned by the notoriously litigious Nintendo. That Kirby is in the latest Fortnite trailer, as Nintendo Life recently spotted. 

You'd be forgiven for overlooking Kirby's appearance - as pretty much everyone did for the first few days following the trailer's initial release - since it's so small and brief. Kirby appears for less than one second within the first two seconds of the trailer. Keep your eyes peeled to the bottom-right corner of the screen shown in the second shot of the trailer. He's half-covered by lasers, but that's unmistakably Kirby. Here's a screenshot of his cameo for those who don't want to scrub along a YouTube timeline: 

This is so unmistakably Kirby, in fact, that Sony and Microsoft blurred out the little pink wonder when they uploaded the trailer to their own YouTube channels. Here's how his cameo moment looks in their versions:  

I'm assuming Kirby was censored due to some competitor's clause or just for copyright reasons - again, Nintendo is famously protective of its IP - which makes me wonder how it got past Epic in the first place. I'm assuming Kirby wasn't added deliberately but instead slipped in after someone goofed around in Party Royale or Creative Mode while prepping scenes for the trailer. Likewise, I don't actually expect Kirby-related content to come to Fortnite (freakin' amazing as that would be). If anything, Epic may well end up removing and re-uploading this trailer in the days to come, sans Kirby. That will probably depend on Nintendo's mood. 

Party Royale mode has already been used to host concerts for Steve Aoki, Deadmau5, and more.