SMG4 Theory: Miyamoto doesn't mind SMG4
Now I'm here to tell you today that there is a possibility that Miyamoto is fine with the existence of SMG4, now let's start.
First case: The run time of SMG4
As you may know Nintendo is quite strict with their copyright as they take down any fan made media that uses their characters, but SMG4 is a show that has been running for over 10 years with millions of subscribers, meaning that the chance of Nintendo being notified of SMG4's existence is quite likely.
Second case: The Ultimate Smash Bros
We all might've listened to SMG4's musical song The Ultimate Smash Bros, and it did make a lot of predictions to the Nintendo game Super Smash Bros Ultimate, first off we got Sans, Bomberman and Dragonborn all joining as Mii fighters, Link's heavy nerf, Knuckles as an assist trophey, Snake's return, and basically over half of the DLC fighters in Ultimate, concidence, I THINK NOT!
Third case: The Nintendo New York store
In SMG4's video "2019 was the biggest year of my life", Luke mentioned that him and his brother Kevin visted the Nintendo New York store where they saw a screen displaying Mario and on it Mario said "Hello my friends Kevin and SMG4, It's a me, Mario", meaning if this store was directed by Nintendo, they had to have known of SMG4's channel and thought his content was good enough to not take down, and who else can do that, the head of Nintendo himself, Miyamoto.
That's all I have for my theory, and I rest my case, also type down below if you have proof that support or disprove my theory.