Did they change the duplicate rate in the last update? I've gotten 2 duplicates the last few days and haven't gotten any since they changed that you almost don't get any...
Once you collect all the sprays every time you roll a spray you get a dupe, ect... you don't just start getting legendaries if you have everything else. But more currency for events is nice
They released a new hero. That means tons of new sprays, voice lines etc. They're the items you're missing so you won't get duplicates until you drop them all. It's simple dude
I was getting nothing but duplicates until they released Brigitte. Try opening five boxes in a row with NOTHING but duplicates. And I still have zero emotes for Mercy or Mei.