Click here to read it: Neo is probably a security
If NEO is a security, NEX can NOT list NEO before security dealers license, It means exchange launch after license or launch without NEO.
Until it is deemed a security, which might never happen, i see no issues at all.
There would be lots of coins that would probably be securities in the eyes of the SEC. I don’t see any problem until there is more clarity and regulation. 
its not a security couse its one gas per one neo i think. but its not characterized as a security by anyone so its ok for nex to trade it.