My daughter is applying EA to few colleges that have deadline of October 15th. After that we said she may want to change her essay for other colleges that have deadline of either November 1st or January 1st.
Can she submit her current common app with current essay for October 15th deadline colleges and then change essay on the common app and submit to other colleges with later deadlines?
I am looking for the same answer! Please let me know what you hear. My son is applying EA to one school and then wants to tweak the essay for two other schools and we are wondering if the original essay gets changed? Glad someone else is asking too! 
Yes. Once you submit the Common App to college X, they only receive what the app looked like at that moment in time. You can make changes before you submit to college Y, but college X will not see those changes.