I don't think there is any difficulty for any DAG based coin to get listed on any exchange. We can look at the available exchanges for IOTA and almost all top exchanges are where it is being traded. Instead of other non issue my main focus is on keep adding more coins little by little at these prices as this is second chance for those who completely missed or underestimated it at first time.
IOTA team is currently working on a module (I think it is called IXI module or so) which let exchanges integrate IOTA very easy. Today exchanges have to create a own procedure to implement IOTA. The new module will make sure that such an implementation is not necessary anymore. By then at least, most exchanges will integrate IOTA.