It seems like we do know the year it was painted fairly reliably, but we don't know that it was Michelangelo specifically that painted it (the article exudes more confidence that I would give based on the inherent uncertainty of these identifications).
The article/video only points to this being proven by research done by Giorgio Bonsanti. If you're curious, you'll have to investigate that angle.
It is frustrating that the article is so coy about the evidence around the premise of the article! But, this website and the youtube video this article is based around both lean more towards pop than investigative.
Why? There were other talented people who produced masterful works at an early age. From the same time as this there's a Dürer self-portrait, also aged 12-13:
I came here to agree with you but then I had the good sense to read the original page which is at the Met (https://www.metmuseum.org/exhibitions/listings/2009/michelan...), and has a lot of background on this painting, including that it WAS actually painted from an existing image (https://en.wikipedia.org/wiki/The_Temptation_of_St_Anthony_(... - worth a look to compare), so my primary skepticism "how could a kid even come up with that" makes a lot more sense that he had an existing image he was copying.
