To be honest, everything but the "4 Mega" sounds like assumptions made out of what we got already.
Technology versus Fantasy: The first trailer showed ancient relic/creature and an arrow that looked infused. I mean it is not as if the whole series have shown a balance of them: Trains, color cameras mixed with medieval weapons. It is also conveniently vague. I am sure many of us were reminded of SS and the third zone.
Dynamic weather: Look gusts of wind! Maybe the weather will be more important for this game.
100 mini dungeons: Aonuma said in the past something to the effect of he wanting the dungeons to be gradual instead and not direct locations. Then you have people thinking the size of the map reminds them of "The Elder Scrolls". I am sure is not that much of a stretch to fantasise withs ome mini dungeons or puzzles. I suppose similar to some TP puzzles.
It really is just that 4 dungeons one I don't really find easy to assume from the trailers and imagery we already got. If this rumour has something to go to, I suppose there will only be 4 bog structure like obvious dungeons, maybe four point locations. Reading your note though, I do agree it really sounds like something that makes you strongly think of Majora's Mask. It does detract more credibility. If you think it is false, then the other points would exist only to give more credibility to the '4 dungeon' one, as the dummy ones, like the fantasy versus technology theme, become 'confirmed'.
The most I am willing to concede for the benefit of doubt would be information taken out of context and not meant to mean that those are the only 4 dungeons of the game as much as that within the game 4 dungeons are going to have some special meaning or connection, most likely to find the main McGuffins or something.