I don't think the successful IEO will lead ethereum to increase prices, the story of the IEO is completely different from the ICO in 2017. if the ICO is raised primarily through ethereum, the IEO is no longer like that. The IEO supported by the exchanges, they all have their own tokens, Binance and Houbi launch the IEO with token HT and BNB. so the IEO will not affect the price of ethereum, if not not affected.
It seems that it can increase ETH price, except that exchange allow people to buy the token or coin using HT or BNB only. But the case is different, people still buy the token or coin using BTC and ETH. So if investors attracted to invest because of the emerging of IEO then it can make BTC and ETH price increase.