I guess, you're right about an exchange token have huge potential. That maybe the reason why some of ICO (an Exchange ICO to be exact), are going to provide their own token inside. Surely, token itself will have potential if the exchange is preferably good. No one knows what exactly will happen, let see.
This exchange seems to seized the opportunity with providing 300 cryptocurrencies and 16 fiat gateways.
If that's the case, implementing all gateways will be not as easy as 123, better to study every little detail before doing this and that. And if the exchange became successful, then, the token will be too.