Canon noncanons and canon differences can actually be rolled into one for me.
Let's start off with the simple things. I was transfem. My name was Linkle, Urbosa helped me through my transition. Robbie literally invented a new organ to help me get estrogen pumping through my body too.
The Sheikah tech did not just simply disappear/turn to dust like the developers say- (Even without the whole fictionkin thing, I still refuse that concept)
Zelda and I kept our new bodies. Or at least- kind of. I still had Rauru's arm for the rest of my life. I did not grow a new one while Rauru's was just "a temporary fix" that was permanent. However, Zelda was changed drastically. She returned to the size of her Hylian self, and but... she was still the light dragon, thankfully with all her memories.
Oh, and there way more sky islands. All the concept islands that were in trailers were there rather than being removed. (Also Monk Maz Koshia's Sheikah Island still exited in the sky-)
The Sage Avatars didn't exist. Well, besides Mineru, but she obviously couldn't give me her power without her following me. But the other sages gave my/Rauru's arm new abilities. Like Sidon's Water Shield would surround me whenever I willed it to much like Daruk's Protection, Yunobo's power let me basically launch fireballs whenever I punched my fist forward in the air, Tulin's Gust happened when I willed it to like Revali's Gale, and Riju's Lightning just happened every time I shot my bow.
Rauru's ghost followed me everywhere and he would talk to me and I would talk to him. But only I and Mineru could see and hear him. No one else.
The Korok Mask wasn't just the mask, it had a full armor set. It was designed to be y'know themed around the Koroks and Deku Tree, so it was just called the Wood Armor- but yeah.
Oh, speaking of "Deku" Deku Babas were an enemy plant like the Evermeans. Deku Babas only were found in forests, but most prominently in and around the Lost Woods.
And since I'm talking about enemies from older games being existent in my canon... Can't forget about the annoying bugs. Yep. Bugs. They were enemies in older games, but over the thousands/millions of years; there were Skulltulas, Tekites, Arurodas, and such that used to be enemies in ancient times, but were just regular sized bugs by our time.
There was a unicorn that lived in Hyrule. She had a pink-magenta main, her fur was a glistening glittery silver, and a curved horn.
Also, Epona was in Mabe Village Ruins/Lon Lon Ranch Ruins
Honestly, I could go on a lot more about flora and fauna that existed in my canon that just didn't in source... So, I'm not because otherwise this ask is going to be so much longer that it already is.