..they have dlc for a difficulty level?
lol you have to pay for a hard mode
Traditionally (I don't know about the newest Zelda games), Nintendo's approach to difficulty was to have a "One Size Fits All" main campaign, and upon completion you unlocked something called "Master Quest", a different mode which modified quite a lot of stuff in the game (but often was not polished and was simply harder on the strength of the bugs).
The problem here is that people think this is "exclusion", whereby they excluded some content from a game to sell on as DLC. This is the inverse; inclusion either of a mode they've never had before (and believe me, difficulty tuning is one of the WORST things to get right as a designer, so it's no surprise they wanted more time to do it), or including Master Quest and this time doing it right instead of releasing a buggy loving mess.
