You yourself made assumptions in your calculations, Nintendo also originally said XCX was 5 times larger than the original and it turned out to be far bigger, they tend to give conservative estimates.

Wow thats awesome, the game looked great its really cool seeing a cel shaded open world game, ive wanted that with many other games but none of them ever got there because they arent big franchises with big budgets, so finally seeing a cel shaded open world game pleases me.

Also are towns confirmed? i read a tweet that said there was none but then someone said that wasnt exactly true so i dont know whats going on but i hope there is towns.

They're confirmed they just removed them from the demo to avoid spoilers.

All estimations will have assumptions. My point is that they never mentioned theirs, so we can't tell how valid their assumptions are and approximate an uncertainty. Takahashi said XCX was "more than" 5 times larger than the original: > is not the same as =. The land-area of Xenoblade Chronicles X ended up only being slightly bigger than that 5 times anyway. I doubt Nintendo would say that this game is 12 times larger than TP when it is in fact 100 times larger. If each block was 1 sq-km, then it would be quite easy for Nintendo to come up with a specific number like 100 times rather than 12 times larger. Unless they were overestimating TP? But per Occam's Razor, I think the simplest solution is usually the correct one.

It was a misunderstanding. There are towns. 

yup like other said towns and npc's were removed for the E3 demo. Aonuma himself confirmed this, so im looking forward to seeing that :D

The plateau area alone from the full Treehouse footage looks to be bigger than Hyrule in TP so 12 times that wouldn't get much further than the surrounding areas and Nintendo said it's 1% of the game the is also no direct quote from any of the development where this 12 times TP came from either.

http://www.neogaf.com/forum/showthread.php?t=1234095

As you can see the 12  times TP doesn't add up and it's believed the comment if actually said is in reference to the plateau and not the entire map.

Naah lol I'm getting the Persona look alike game for WiiU next, Zelda as a series is overhyped imo. I bet this will get 10/10's but I'll play it and be disappointed like I was with OoT. 

Going off of this
Twilight princess:

http://zeldapower.com/images/tp/maps/item_map.jpg

Here I used the bridge of Eldin as reference. Its width is roughly 6 times the height of Link (again assumed to be 1,80m) thus about 10,8m. The Twilight Princess map seemed to be a very detailed at up to scale representation of Hyrule therefore I assumed the 10px from that picture as the width of the bridge to correspond to 10,8m. The whole map 1536x1968px is thus 1659 x 2125 m^2, but again only about 27% of the graphic are Hyrule area. Measuring the scale on the bottom of the map leads me to the assumption that it is about 500m long.

I then let link walk quickly along the bridge, which took me about 80 sec walking (32 sec running) corresponding to about 133 metres. I measured 110 px = 119 metres. So I think I am not too far off here. I also measured some other distances and got similar results.

Xeno X's world will still be FAR larger than LoZ: BoTW.

To be fair, Xeno has to accomodate mechs.