Can't say if it's the same noise (or issue), but I had a problem similar to this with my '16 RGU. Brought the bike in under wty several times. Finally had HD Factory rep look at it. Unfortunately, no one but me could hear the noise (whistle, whatever). Needless to say, it never got resolved and I decided to let it go.
Since then I've ridden 2 other Road Glides as well the FLTRUSE I traded my FLTRU for this April. It has the same noise. Not always at the same speed, but generally occurs in the 50mph range, give or take a few MPH.
Sometimes it's more noticeable than other times. Perhaps temperature has some part in this or direction/wind speeds, etc? I don't know.
I will go up the my dealer and see what they know about this part....