You can watch the trailer here. Medli is so adorable, I always really enjoyed playing her in the Wind Waker. The Earth Temple is easily my favorite dungeon in the game. And it will be awesome to get more into action with her. But similar to Tetra, I'm not a fan of her squeaking sounds. This might get annoying easily and this is something, where Koei Tecmo seems to have some issues. In terms of design and movesets the characters are all really well done, they do the source material great justice. But certain characters like Tetra, Twili Midna and now Medli are a little bit off on the sound department.
Anyway, the Master Wind Waker Map does use an 8-Bit variant of the "Cursed Sea" theme, which I really like. That's a good choice. Other than that it doesn't really look that different, it does have a different background and the red borders, similar to the original Master Quest Map, but overall it looks quite identical. But this shouldn't be surprising and if you consider that this map on its own only costs 2€, you can't really complain. I personally really enjoyed the original Wind Waker Map, so I'm looking forward to it.
I still hope that they go for the Link's Awakening 8-Bit style with the upcoming maps. They all revert the maps for the console Zelda games back to the NES 8-Bit style and it would make sense to go for the GameBoy (Color) 8-Bit style with all the handheld Zelda games. Also, the Adventure Mode doesn't have a complete overview of the maps anymore, so the maps theoretically could have any shape. However, going through Koholint screen by screen would be too large, twice as large as the original Adventure Map, but I suppose they could just use two screens together as one.
Of course the likeliest scenario is that they keep doing the NES style and just remake Koholint in classic 8-Bit. That could also look interesting, but as a fan of Link's Awakening I personally hope for a more accurate treatment. They haven't done stuff like villages on the NES maps (only rough outlines of castle and Clocktown), while I feel that areas like Mabe Village are too important to be lost in translation. And actually for Koei Tecmo it would be less work to simply reuse the world of Link's Awakening and its items, instead of converting it all into the NES style.
And they can keep using the style for the upcoming handheld Zelda maps. Portraying Lorule in 8-Bit certainly would work better with the sprites for Link's Awakening, because it's closer to the SNES style worlds. And if they do a rail map for the Phantom Hourglass & Spirit Tracks Pack, they could use the rail sprites from the Oracle games.
We'll see about that in two months. The Master Wind Waker Pack and Medli are out next week, on May 19th.
Looking at the new materials a little more closely, you can see that Medli is getting her ugpraded weapons and her hearts on the map. This shouldn't be surprising, since she's a free addition similar to Cia, Volga and Wizzro. Overall this DLC seems to be quite close to the original Master Quest DLC on the Wii U.
The map even has "Master Rules", where one of them is "No Fairy Magic". I bet that this rule will always come into play, when fairies would be really useful, so you're really appreciating the feature afterwards. And I hope that they don't bring back the "Don't get hit" rule, because that one is really annoying on the Nintendo 3DS. It already was on the Wii U, but with the rendering issues of this game it's ten times worse.
Also, I hope that future DLC characters will be handled the same way as Medli. In Japan they don't sell the characters separately anymore, so maybe Koei Tecmo has listened to the feedback, where the Wii U DLC characters were quite boring on their own, without any missions.