With the news that two out of three new characters joining The Arrow/Flash universe already filled in
So now there is only the third character left who happens to be in the description An African-American male in his twenties will fill the role of a regular, street smart guy who unexpectedly gains powers, and then, as part of the team, regularly quips about the insanity of the situations.
Well Static is normally the obvious choice but then why would they do a web series with him so I think this couldn't be him so maybe.
After Static, Black Lightning is a plausible candidate as they have used him in the animation Young Justice and would eventually become a mentor to Static in that version.
Mister Terrific is another candidate but considering that the person is street smart and not just smart as he is I don't know if they are describing him.
Again he may not match the description completely but still might turn out to be him.