Do you think that this decision is being partially driven by the reduced capacity percentage at each park and thus reflective of decreased attendance?
I do. without knowing the details of WDWs contract with Mears, I suspect the pricing structure is a combination of fixed/base and variable costs. Like a flat rate plus an increased factor for each passenger or bus that goes from MCO to WDW and back. Perhaps, due to covid, the reduced number of guests visiting WDW have fallen below the cost-effectiveness of even the lowest price structure on the contract.
My thinking is that when WDW attendance starts returning to normal, we will see a return of DME - but it won't be free, similar to the cost of transfers to port Canaveral for a Disney Cruise.