You'd think gun right activists would more concerned with this reality. But I can assume the skin color without reading the article and that is a more uncomfortable reality for them to acknowledge; the reason some of them need to be armed.
I think it's relevant because it's evidence the teen was not a threat. I don't think it's implying an armed individual would automatically be a threat.
There are articles that do draw that false equivalence, and they deserve being called out. I don't think this is one of them.
Also, do you believe that a suspect needs to shoot first before being considered a threat by police? I would say "armed and brandishing" would make the individual a legitimate threat.