My response was presented at the OP, not your further discussion.
You are correct that you do not need an old RMI with metal needles to fly an NDB approach. "Raw data" may be displayed electronically, though I don't think the FMS can manipulate them. I've flown several NDB approaches in the 744, and it has electronic display of ADF bearing (as it does for VOR course and LOC/GS). Of course, I always create an overlay if one is not already programmed, though legally the ADF "needles" still have to be displayed on the ND, and I am required to "refer to" them.