Could Iron Galaxy be bringing Fortnite to the Switch? It's the same team that handled the port of Skyrim to Switch, so they certainly know the system. The potential for Fortnite on Switch might have been leaked as part of a job listing for Director of Game Design at Iron Galaxy. The job listing as it supposedly originally read is listed below.
"Iron Galaxy Studios is a well-established independent game developer who has partnered with the titans of our industry to ship more high-caliber games than any other indie developer. Our best known creative works are, the critically acclaimed Killer Instinct, and Divekick; which are complimented by our technically superb Fornite and Skyrim switch ports. We are looking for an inspiring self-starter to join our Iron Galaxy family and embrace the leadership role of Director of Game Design."
The page no longer has that same mention. I did a cached search and found nothing, and checked the source code as well, but that was a dead end too. The one bit of truth we know is that Iron Galaxy has indeed worked on Fortnite. Perhaps someone else out there better at internet sleuthing can hunt down an original version of this job listing.