All airlines 'participate' in DME. It is the 'going back' to MCO that sometimes presents an issue. There are airlines that participate in the RAC system (remote airline checkin). If you are flying home on one of those airlines, you can check your bags right at your resort and get your boarding passes issued right there. There is a sticky at the top of the page that gives you the current airlines that are participating in this program.
But, for arrival into MCO? You can arrive via yak and still ride the bus. You can fly in on any airline and use the provided yellow luggage tags to get your bags right to the resort without having to claim them. The airline you arrive on makes no difference when it comes to using DME for your transportation to your WDW resort.