I guess there's the other tutorials but they only cover a minor amount of stuff. The Atom one would have been good for a new person trying to learn Atom but eh, didn't give me any insight into anything I didn't know.
But like you said, in future games it could be developed into more. Like for each tutorial you pick the character and then you get a tutorial for that character about whatever tutorial you picked, e.g You pick like Scarecrow and you picked the "counter zoning" tutorial so you get a walkthrough on Scarecrow's tools that allow for him to get past zoning like teleport, J2, F1 etc.
I get that that's a lot of work for a tutorial though so maybe not.