Platform-exclusive items (Sweet Tooth, Hogsticker, Armadillo, Mario/Luigi NSR, Samus' Gunship, etc.) will not be accessible through your Epic Games Account, nor will DLC that is unlocked via retail disc. Platform-exclusive items will still be accessible on the platforms where they're available.
Premium DLC Packs with licensed content purchased on the Nintendo Switch prior to Free To Play (Back To The Future, Jurassic World, DC Superheroes, Fast and the Furious, Ghostbusters, Knight Rider, etc.) will not be accessible through your Epic Games Account, but will still be accessible on the Nintendo Switch platform. We are working to make Premium DLC purchased on the Nintendo Switch accessible across all platforms.