It might use a BSD kernel, but that's not the license to it.
Going from the names and dates in the attribution, it's from a 20 year old version of zlib.
This is fantastic. Nintendo's OSes have traditionally been awful at least from a technical perspective. I'm looking at you, Wii U, and your 5 second wait to open the settings app.
I was blown away by how poor/slow the Wii U interface was compared to other modern gaming systems.