Its Psierra117 Modding Time again 
Its stated on the Product Page, that the Gen2 dGPU Bay mainly has changed Mylar. Thats an easy Fix to reproduce without buying a new bay cover.
Gen1:
Gen2:
mine
moded with already one fan added.
Done, additionally i took a look at the fans and thought, which Part could whistle, well i copied the mylar/Vinyl Strip from the Cover and coverred the small hole where the ribbon runs through.
don’t mind the electrical Tape, thats an “old” Try of mine to reduce turbulence and even the pressure loss.
Overall subjectively, Yes that helps to reduce the whistle and whine on the gen 1 dGPU Bay. When the new Fan comes to avail, i definitly think about getting a pair and compare it.
and i know its not uneven cpu thermals related, but as my whole heatsink mods are here i wanted to keep em here 
And yes the dGPU has also been swapped to PTM long long ago.