I haven't personally got the last two codes yet so I can't test it out. Anyone able to?
Hello! Shigeru Miyamoto of Nintendo here. As promised, I'm here to tell you how to make use of the special code you've obtained if you've managed to find all ten of the secret data files.
During their latest treasure-hunting adventure, Captain Olimar and his Hocotatian crew recorded a series of secret Expedition Logs, and entering the special code allows you to access them! The secret data files are hidden in various locations.
If you haven't yet found them all, don't give up. Keep on searching!
♦ To view the Expedition Logs, select the blue internet browser symbol below, and enter the special code when prompted. Please note that the Expedition Logs can only be viewed using the Wii U console's internet browser.
It's a 43 second video, I just watched it.
Features Olimar detailing why he's on planet, collecting treasure etc.
Then Louie features being chased by monsters with Pikmin dying.
Then it ends with Olimar saying that the local wildlife aren't laying out the red carpet for them.
That's it. Possible DLC hint? Seemed to feature a new area.