I think natural adding process to exchanges it's the better choice. I see no reason to delay. 
define natural adding process
To add an ALT to an exchange do you need to submit it? Always?
No. Not all coins must be submitted to get on an exchange. If the exchange ops determine that a coin has trade value and that others would also agree with this , then the exchange ops themselves would seek to add said coin. There are many element and matrix used by exchanges to make such determinations.
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