As soon as the time comes, exchanges will get the full nodes
officially. This is developers plan and they have
full right to demand to comply with their terms. 
At the moment, Only private individuals can do it. The Exchange is not private individual, it is a company.
Where I can read about it?
Think about it - why Poloniex/Bittrex/Etc not do that? Why they do not work with IOU? Because they are a good
companies.
