The Switch port for The Witcher 3 will include all of its content on the cart. As in, CD Projekt Red have shelled out for 32-gig cartridges for this game so that everything will be on the cartridge, and no external downloads are required.
I was planning on picking up The Witcher 3 on Switch anyway, but now I hope this port is crazy successful and sends a message to all other publishers releasing games on Switch. Including all the content on the cartridge is something that should’ve been required for all Switch games from Day 1, no exceptions, and it’s a standard that needs to be set in stone right now.
No more physical/digital hybrid releases (the Mega Man Legacy Collections, Resident Evil Revelations 1 & 2, Final Fantasy X/X-2) or games that require an external download to play because the publisher is too cheap for 32-gig cartridges (Doom 2016 and Wolfenstein II: The New Colossus). Hopefully The Witcher 3 on Switch will do well enough to kill off both of those types of releases for good.