It's only a matter of time before we will see DeepOnion listed on every respectable exchange.
Seeing the Onion Fiat pairs is a nice bonus.
Dont get me wrong here, but this is not going to happen any time soon.
Listing coin on certain exchange requires time, money (usually BTC amount) and some conditions to be met, so it depends mostly on Deep Onion team and their effort.
There is no major exchange that will list ONION out of the good will, they will either ask for $$$, or ONION need to win some community vote or similar.