It's gonna such for you when I have all my original games in 20 years and your HDD is dead.

If that happens, you can just re-download them onto a new HDD. And because your save data is stored separately on your console's internal memory, it will be absolutely fine. In fact, likely safer, as your precious discs stand a great chance of getting lost or scratched over the course of 20 years, no? Yes. Unless of course you lock them in an underground safe and never play them, or move away.

No, you can not redownload them... why? Because your original Wii-U will have died by that point and your games are tied TO THE SYSTEM. Also, and believe me, I've given this alot of thought, "redownloading" only works when the parent company is still hosting the data for you to download. So if Nintendo isn't in the business of keeping 20 year old games on some server for Wii-U owners in the year 2034? How are you gonna get that download? You're not going to be able to do that.

A hard drive breaking is about as likely as a disk breaking if not less likely. Second everyone else besides Nintendo link their games to accounts not consoles so you could redownloaded. 3rd if your Hardrive breaks you don't think the save data from a physical game will go bye bye? 

Bayonetta on 360 is 6.8GB.

lets compress the raw file to jpeg.

I'm as baffled as you are. The file size tripling makes no sense, especially when the additions aren't terribly memory-consuming. 

The best theories we've been able to come up with so far is that either it's a mistake, or Bayo 1 on Wii U is uncompressed, the latter of which makes little sense as they're pushing it as a downloadable title on a system with a maxiumum 32GB HDD.

Europe is getting an incredible day one edition, i would have to be insane to buy digital.

Besides, you can use an external disk. Why the drama?

No reason to be baffled.

Uncompressed, dual-audio is a very, very large space hog.

I am buying a physical copy, however I have a 500Gb HD just in case :)