See the sticky at the top of the page regarding using ME as a luggage service. It is not acceptable policy to do so.
When you check-in at the ME desk, Disney begins the search for your luggage. They won't know to go look for it, if you have not checked in and your luggage may stay at the airport baggage claim.
If you have any inkling that someone is going to pick you up; do not use your yellow tags at your home airport. When you arrive, if your friends were not able to pick you up, you need to retrieve your luggage from the baggage claim and take it to the bus - it is the same if your friends do pick you up, so it would be no different. Either you will be taking your luggage down to the ME area or wherever you have arranged to be picked up.