I think MT (to take advantage of MC) can be programmed... from scratch. So it is not a feasible option for ED since their advantage is the engine they already have. However it is a smart move if they can spare resources for engine R&D.
The engine should be event driven, with synchronization points. Since graphical programming relies on one fact, the frame displayed, it is a good point to use it for that purpose, as I think it is being used today in ST.
However, I do not try to tell ED how to do its work. Just a bit of smart thinking :D