[2019] Halloween event not giving all of its rewards?

I've noticed that other players who have completed the 2019 Halloween event have received noted pumpkins and Halloween masks. When I completed the event, though, my inventory was filled with non-tradeable items from previous Halloween events. Destroying these items and talking to the NPC again (as well as Diango) didn't prompt the receipt of any further items. Are the rest of the rewards gone forever? Should I have tried to empty my inventory before completing the event?