the only difference is the middle letter. ICOs are scamming people by calling themselves initial "coin" offering and IEOs are scamming people by doing the same exact thing while calling themselves initial "exchange" offering.
the end result is exactly the same with different speeds at which they dump and exit. as IEOs are already supported by and listed on an exchange they can dump and run away faster.
yes maybe you are right. but IEO is better for some projects. I see there is still hope for those who want to invest, as long as the project is in large exchanges like binance. indeed overall IEO and ICO are the same. but quality exchange will make the difference.