As far as I know, the VNAV descent defaults to 3.0 degrees, so it makes no difference what the winds are. I would imagine the downloaded winds are used for fuel planning purposes only.
If you had a steady 80Kt tailwind on descent then it would make sense that speedbrakes would be required as the wind would be 'pushing' you off the computed 3.0 degree descent angle.
I'm no real life pilot but I would hazard a guess that this is correct.