Difference between "over" and "on"
The question is:
"All the employees at SEI Corporation are invited to the meeting _____ the new internal communications system that the company is about to bring in."
The answer from book is "on" and I agree with it.
However, when I check Oxford: http://www.oxfordlearnersdictionaries.com/definition/english/over_2
At the meaning no. 12, it says that "over" can also mean "about something". So I wonder if we can use "over" in this sentence. Is there any difference between "on" and "over" in this case?