I would display a needle if it formed any part of the procedure, but still fly it from the FMS. Again, you can legally use FMS as long as you are displaying raw data.
From one of my past types (EMB 500),
The Garmin integrated avionics system makes extensive use of GPS.
ADF and VOR DME procedures are flown as GPS overlay procedures. Display of the primary source upon which a procedure is based is required.
VOR/DME and ADF can be selected manually and displayed on the HIS.