I like idea that there’s no proof of these incidents so they’ll either think its being covered up or he’s from another universe (don’t know if they’ve dealt with that yet though)
This is the Young Justice Universe, not New/Prime Earth. I don't think being from another universe is that high on the hypothesis list based on the info they have at the moment.
The novel is good but there is a little plot hole. why is the justice league accepting his stories on his adventures so easily , at least batman would try to find any kind of evidence to his fights, and if he didnt find any he would get suspicious