The game is on a complete different engine compared to brink now they could have converted stuff over, but if you look at portfolio pictures of some of the 3D modeler guys, you will see renders of the weapons with different sights. Also every primary weapon has a picatinny rail in a location for sights, even if the gun itself uses the standard ironsight.
Now that doesn’t necessarily mean that attachments are coming. But at one point SD clearly cared enough about attachments, that they modeled them and programmed a system to use attachments. Maybe it was part of a more realistic iteration of DB and they scrapped that. On the other hand it is a f2p title and somehow they have to make money. Game can’t survive on different camo loadouts forever.
As for the folder, quite a few of the default sights are actualy attachments. If you use that console command to test out weapons, they will often not have the respective scope/sight or stack the current sight on top of the old one.