I though that decentralized means that the users hold their private keys and not OpenLedger. The amount of RISE being send to LiveCoin is almost the amount from the users: https://bts.ai/a/OPEN.RISE
Clearly OpenLedger did something.
No,,, holding your own private keys just means that the ownership of funds belongs to you, in which case this is not a custodial exchange,,, meaning they do not keep custody of your cryptocurrency.
This is actually what most decentralized exchanges are about. They only decentralize ownership of funds and nothing else. There are many other aspects for decentralization to take care of.