This is some nice work! However, I would like to make some points/observations/clarifications:
1) The Japanese text you screenshotted says that her Final Smash is the Triforce of Wisdom. That line is not talking about what game her design came from. The line you screenshotted is the line that is displayed when they are talking about her new Final Smash.
2) When talking about her design, Sakurai said in Japanese, "this time, her design is from Triforce of the Gods". This is ambigious because it could mean just the original game, LttP. However, I think it would be a more reasonable assumption that he's talking about the series "Triforce of the Gods" in general and not necessarily specifying LttP over ALbW, since in JP they are both the same name, except one just has a "2" on it.
3) The English translation of the Direct is definitely a mistranslation, as explained in point 2. There isn't reason to interpret what Sakurai said to mean that he was specifying one game over the other, or at least definitely not the second game over the first.
4) I agree that, as you have pointed out in your analysis picture, there are quite many elements that are closer or matching the design of LttP Zelda over ALbW Zelda.
5) There are also, however, many elements that are closer to ALbW, which you have not pointed out in your picture.
Examples are:
-the shape of the pink flap in front of her is more rectangular, where as in LttP it gets wider near the bottom
-the overall coloring is much closer to ALbW
-the cape is shorter like in ALbW, and is not as long as the dress itself
-the cape is not as wide as in LttP, where it "curls" around her such that you can see a bit of the back of the cape from looking at her front; it hangs flat on her back
-the design of the embroidery on the frontal pink flap thing is like several points in favor of ALbW if you are going to list every detail: the gold border being VERY near the edge of the pink thing: the gold details inside of that gold border matches the ALbW design, though is simplified; notice the much lower position of the triforce; notice the LttP design is missing the gold symbol thing below her belt and above the three small triangles; the triforce of wisdom is not red
This is in addition to one of the biggest things that you mentioned, the shape of her hair and her bangs. And it's not just that her bangs are over her crown. First, bangs in LttP go so far back that they reach behind her ear. Second, the "bangs" are swept to the side of her forehead such that they do not rest above her eyes. These are barely bangs by definition of what bangs are, even if the reason is because the crown is holding the bangs off to the side instead of letting them fall across her forehead. Also, the part at which the bangs bend over and hang down is pointy in LttP, but round in ALbW.
6) I disagree with some of the points you brought up, such as the crown. While the Smash U crown does not match either design, it is clearly much closer to the ALbW crown, with it having spiky parts on the side of her head behind her ears, the shape of the jewel at the front is a diamond shape, the jewel and the gold "frame" around it are centered on the "ring" of the crown whereas the gold "frame" around the jewel in LttP's crown is jutting below the rest of the crown and does not stick out above the "ring" of the crown, etc.
Overall, the design is a pretty good balance of both LttP Zelda and ALbW Zelda, which is reflective of my interpretation that Sakurai meant to refer to both games in general, and not one or the other. As an example, note that the blue stripe at the bottom of her dress is thick in LttP, but thin in ALbW, while in Smash U's design, it has TWO stripes, one thick and one thin.
While you may wish to be able to quantify it in such a way to say there are a higher number of details resembling LttP's than ALbW's design and it is thus based on LttP, there is no denying the many aspects taken from ALbW. The hair, the crown, the cape, the coloring, and the golden embroidery design on the front of her pink thingy are big aspects of her design that are based on ALbW. The Smash U design is not solely a LttP Zelda design, nor solely a ALbW design. It mixes many elements from both, with a little Smash originality as usual (mostly the crown, simplifying the details of the gold embroidery on the front, and her eye shape), and as such you cannot make the claim you did in this thread's title. It's most reasonable instead to say that her design is based on the "Triforce of the Gods" series in general.
Note: ALbW Zelda is not "a small child" either. That is just the design and the style. Small childs do not have busts like that. Also, it's obvious from the story that she is not a small child, nor is Link, or any of the adults in the game, who are all drawn in the same semi super-deformed (chibi) style.