I was really hoping the Black Edition Non-Backplate cards already had the thermal pads installed since I requested them awhile ago but got no reply, they just arrived today so I guess that confirms they don't already have the pads installed. My question is, should I even install them? My temps seem safe according to HWmonitor, the highest temperature I get is 76°C in a 21°C room. Is there any other reason I should install the pads? 

yes to be on the safe side. 
 

As it costs you nothing, why not give all the cooling benefits you can to your card?
Install'em.....

My pads came yesterday and I installed the new ones last night. My new 1070 SC Black RMA card
that got here last Friday to replace one of my cards that died had the new bigger pads installed
already. All is as it is supposed to be. So change them over takes about 30 minutes or so.