There's no way that getting rid of DME is a Covid thing. Look at the timing. Its going to go into effect in what is assumed to be after the Covid era. If anything, getting rid of it will cost Disney money, as it makes it hard to travel to Disney without a car. My hunch is that they're getting rid of it because they expect the Brightline to take over that function.
Remember, MCO is not that close to WDW. Its silly to think that Uber/Lyft is a great option for that distance. Uber/Lyft is designed to be cost efficient for traveling around a major city where you're only going 2-3 miles. And even crazier option is forcing people to rent a car just for that trip. It costs Disney almost nothing to pack a lot of people into one bus.
This has Brightline written all over it.