You don't need any documents. How do I know this, well because my documents never came. This was a
travel agent issue using the wrong address for my documentation. I should have used
Dreams Unlimited 
I was freaking out because I had no luggage tags, no coupons, no ME, nothing. I did get my magic bands because those were shipped directly to me from Disney and they had my correct address.
My travel agent laughed at me, actually laughed at me, when I called her 2 days before our trip stating I had not received our travel documents. She said, "you don't need them, just get your luggage and take it to the ME check in area and either take it with you or they will take the luggage there for you to deliver to your room."
Of course I was still stressed out, as I am a type A person, planning the vacation to the last detail. But what could I do but just go with it. We got off the plane with our magic bands on, picked up our luggage from the carousel and opted to take the luggage with us on the ME, then we have it with us rather than waiting up to 3 hours for it to show up in our room. I held me breath walked up to the entrance of the ME at level 1 at the airport and scanned my magic band. Mickey went green and the girl asked which resort and pointed us to the POR line. 15 minutes later we were on our way. When I went to check in I let the desk know we did not get our travel documents and asked about our coupons and return trip via ME. The cast member printed out the coupons for me and said the ME pick up time for my party will be delivered to my hotel room the day before we leave.
Everything flowed seamlessly and it turns out I freaked out for nothing. The ME doesn't care when your flight gets in just the day it gets in, since flights get delayed and sometimes come in early. Don't worry about changing your flight, you really only need to let them know about your return flight and even then you can call them once you are at the resort. The same travel agent on a different trip (should have learned my lesson then) did not update ME about our departing flight. I still got a ME document the night before check out with no time on it, but a number to call to make our reservation which I did the night before we left and had no problems.
Have a great trip!