They don't increase the chance for exotics they eliminate them. The whole exotic system is broken. I got 1 exotic engram all day yesterday. Previewed it for over a half hour till it showed 3 exotics I didn't have then it gave me my umpteenth sweet business that wasn't even on the list. I got the business all right. I still can't get an Orafice Rig after farming for it. In the preview it shows that the new weapons are already in my collection. I never got them and they are not in my vault collection either. So when no repeat exotics comes up will the game already think I have the Colony or the new hand cannon?