Information comes from Amazon France so it's more than a rumour, it's practically official.

https://www.youtube.com/watch?v=nxoAYD8ZW68

Ahh ok well atleast you get an amiibo with your DLC. That's something I guess.

I can already tell that this is going to ignite the "amiibo do too much" fervor once again. I'll just say for now, that it would be best to wait for official information. But if I have to take a bet, I would say that this new dungeon will basically be like a "Cave of Ordeals" part 2 essentially.

that kinda sucks... what if i can't get the Wolf Link Amiibo cause "collectors" are gonna buy them all?

Then it is similar to Splatoon's amiibo integration, at least here in Europe, retail DLC stuck in the Special Edition.

Even though this adds something, I'm still not interested in this port.

It is included in the physical packaging so unless you buy it digital there is little to worry about.

Meh, I really don't like the way Wolf amiibo looks, but I guess I might have to cave in.

That's good - better then unlocking clothing items!

I disagree. Clothing items are a better content to give than a new dungeon whose extention might lingers between five to ten minutes max.

Just imagine playing the whole game with Link dressed as Bayonetta and you see which is the real deal, that or a Cave DLC.

That's pure speculation on your part. It can be what you just said, a full lenght dungeon, a Boss Rush mode... We don't know.