Probably because graphic from that tech demo in open would be too much for Wii U.

We get a lot of old classic games added to PSN/XBL/eshop even without any HD treatment. And among the games that get an HD treatment, there are games from the PS2 era like Zone of Enders 1, and even the PS1 game Final Fantasy 7 was released in HD for PS4. So if you want to talk about games with aged graphics, there you go.

A remake for curren gen consoles take a lot more effort. I don't think we even have one yet?

And looking at the game on Dolphin, it looks alright. Iäm not trying to gouge my eyes out or anything.

This tech demo was actually running on a weaker pre-production WiiU

Winwaker HD is exactly what I'm expecting. An HD port with some improvements. Not a remake. Resident Evil 1 Remake, MGS Twin Snakes, etc, those are remakes. I don't thing there's even been a remake of a PS2 era and up game yet for a home console. (But Yakuza 1, Resident Evil 2 and Final Fantasy 7 Remake are on the way.)
And Nintendo has no established pattern when it comes to how they treat re released games in HD seeing as there's only 1 so far (to my knowledge). And that's Wind Waker.

OoT and MM are portable games with a much lower budget. That's why I said home consoles.
It's not about following trends, but about money. That's why full blown remakes for HD consoles haven't even happened yet. And Nintendo are clearly prioritizing profits when it comes to the WiiU. That's why there still hasn't been a new price cut after nearly 3 years, and the only new games announced at E3 this year are a Tennis game and an Amiibo Party game. The console is well on its way to become Nintendo's worst selling console ever, so I doubt they'd grace it with a full blown remake.

Twilight Princess doesn't need much more. It just needs to look clear on an HD display and be playable. Anything beyond that is a bonus. Other games don't only recieve an HD port instead of full remake because it's a trend. It's because it costs significantly more to do a remake for a current gen system. Time and money that can often be spent better on making an entierly new game.
If there's any trend worth talking about with Nintendo when it comes to the WiiU, it's them being very economical. Mario just had his 30th anniversary this year. And Nintendo released Mario Maker to celebrate that, and Mario Galaxy 2 was re-released on the e-shop without any HD treatment or even any upscaling. It looks exactly the same, which means blurry. No matter how good the game looked on a CRT TV. So your idea about how they're not going to release a "lazy" HD port for Zelda's anniversari doesn't sounds convincing. An HD Twilight Princess with some upgrades like Wind Waker HD would be quite a step up from the straight Wii port of Mario Galaxy 2, alongside the presumed 2016 release of  Zelda WiiU.
And if they were to make a big budget remake for a Zelda console game, even if WiiU had been successful, if popularity is a factor then they'd be more likely to chose OoT which is arguably their most popular Zelda game, which has even aged badly in terms of gameplay mechanics, and not just graphics.

This looks quite presentable btw:

The real Zelda Anniversary game is Zelda WiiU, and that's what they're spending most of their resources on.

Because they are screenshots from a Youtube clip. You have to use your imagination a bit, unless you're not familiar with how games look on Dolphin. This is what it looks like from Dolphin's official homepage:



Having a hard time seeing what's going on here too? Because I sure don't. (Right click and View image to see the full size.) I've seen the game run on Dolphin before, and it looked just fine. It depends on what hardware you are using, as emulators are quite demanding. If Nintendo were to make an HD port, they could improve some of the textures, and even add more vegetation and other things. This is far from a game that's in dire need of a remake. You just don't seem to be familiar with what HD can do to the game, since you quoted how blurry the previous screens looked.
That there could be compatibility between NX and WiiU is a point towards a remake being more logical. And I thought of that, but right now there are a lot of ifs. If it will be compatible, and if NX will even be successful. And there are a lot of other things pointing in the other direction.

I'm with you on the idea that Nintendo needs to soften the blow a bit for Wii U owners, in regards to how they're already talking about the next console, support is diminishing, and possibly tthat Zelda WiiU could be cross platform. Or rather, I was, a few months ago. After E3 I thought WiiU owners should at least get one more noteworthy title, like F-Zero or Metroid. (Although Metroid Prime's director said after E3 this year that they haven't begun development on a new console Metroid, and that it would take around 3 years to finish, so by that time the game would have likely been moved to the NX console.)
But people argued against that, and I've since then started seeing it as not very realistic. So I'm thinking it will be more along the line of games like Mario Tennis rather than something like Twilight Princess Remake, or F-Zero WiiU. I hope I'm wrong, and maybe there'll at least be a cross platform game shared with NX. Perhaps Pikmin 4 will be that game.

Super Mario Galaxy was just a VC re-release, TP has HD in the title? Yes, that was my point. They put zero effort into it during Mario's 30th anniversary, and you assume they will put the outmost of efforts into the Twilight Princess game during Zelda's anniversary. They're already making much more of an effort for TP HD than they did for the Mario Galaxy 2. Which is not in need of a remake, but HD would have been nice.
As for what resources Nintendo would spend, hiring another studio is spending resources. Money = resources. With money you can hire more people, or outsource, etc.

I'm aware of Pokken, but that game began development in 2013, and a WiiU port was likely part of the deal from the start. Long before they realised that they weren't going to be able to turn things around for the WiiU. It also costs Nintendo less since they let Namco use their extremely popular IP for the arcade version. So that's not a sign of Nintendo's comittment to bring new games to WiiU from here on out.
The rest of the games you're mentioning are also games we already knew about that already began development before. Shin megami Tensei x Fire Emblem was announced in 2013 for example.
You're misreading my post. I'm not saying no more games are coming in 2016. I'm saying Nintendo didn't announce any new games for 2016 or beyond at E3. And they've always done that. Except for this year.
And I didn't say anything about Mario maker being bad. In fact, I think it's a good game, and a nice way to Celebrate Mario's 30th anniversary. I brought it up because it's a game that celebrates Mario's 30th anniversary, just like Zelda WiiU will be a celebration to Zelda's 30th anniversary. And alongside them, we have the re-release of Mario Galaxy 2, and the Twilight Princess HD port. For the former, Nintendo put in zero effort, even though the game could use an HD upgrade so it doesn't look blurry. And you're telling me that Nintendo can't get "lazy" with the Zelda port, when giving it HD treatment is already putting more effort into it than how they treated Mario Galaxy 2.
As for Ocarina of Time's popularity, accoring do vgcz OoT sold slightly more than TP, though vgcz can often be wrong. But either way that's besides the point, as sales don't neccesarily measure popularity. Twilight Princess was on a console with a 100m userbase largely consisting of casual gamers and soccer moms who are no longer interested in consoles, and have moved on to mobile gaming. Resident Evil 6 is Capcom's second best selling RE game, and their second best selling games of all time, according to Capcom. But it's certainly not one of the most popular RE games. It's the most heavily critisized mainline RE game, and got the worst reviews from both critics and fans alike.
Ocarina of Time is the most critically acclaimed Zelda game, and it seems to be the most popular3D Zelda. (Though my favorite is Majora's Mask.)