I don't know if this has been posted before but I think the leak showed us the final roster, and I am going to explain why.
I agree the CSS looks unfinished but you have to keep in mind, customization is off therefore the Mii Fighters aren't in there. Having them in there might pretty up the CSS and make it make more sense.
What I can't say is why All-Star mode is locked, but I do have a theory. Sakurai said something like "assist trophies will figure into all-star mode." Maybe every character was unlocked, but all-star mode was disabled because of something with assist trophies? Also, wouldn't it make sense for them to show the ESRB all playable characters, but skip over something relating to assist trophies?
Just my two cents, forgive me if this argument was already posted.