Even though I played the MCC on Live during the specified period of time (from November 11, 2014 through December 19, 2014), I never received anything telling me I have access to ODST. Why is this so?
You should have recieved a message from Xbox Live with a code, but if you missed it then the message would have expired. You can still get a replacement code, details are in the MCC FAQ in my signature. Scroll down to the section on ODST 
Thanks stckrboy, I’ll try posting in that forum.