ICO that use an exchange to held their coin offering or in short IEO already run for a long time. it became popular recently because of some big exchange that run it and become a hype because of it's succes.
because of this hype investor will most likely choose ICO that run on exchange or IEO rather than normal ICO.
so to answer your question.
so can you give your opinion on whether IEO or ICO will survive on the long run
both will survive in the long run because IEO is just ICO that held on exchange.