Learning about IEO is a great thing MPCX is the best to a greater future
IEO is simply an avenue for projects, just like MPCX to raise funds utilizing the assistance of a cryptocurrency exchange who serves in the capacity of an escrow because the funds are deposited in the exchange and used for the purchase of the tokens.
I love your explanation on the concept of IEO, but i would like to add that IEO seems more secured than ICO since the exchange which as you said serves as an escrow and would be involved in the fund raising. The exchange is entitled to its commission and has her reputation at stake if the project turns out to be a scam and as such would carry out a feasibility study to ensure that the project is legit.