I think IEO can not have a long live as ICO. In 2017, ICO was the accelerator of Bitcoin, Ethereum and the whole crypto market, it made the biggest bullish in cryptocurrency history until now. While IEO only make exchange tokens increasing price in short term, IEO doesn't have positive impact otherwise it brings negative impact to crypto market.
But I seeing IEO same as the ICOs with an upgrade. Same things happen in IEO, but they just skip the period of listing in exchange. They introduce the token directly into the Exchange. but here is the point. previously project came into exchange project team made some progress on their project. But in IEO there is no that time period. But many people interesting about the IEOs.