They are for trials of osiris. Im guessing it will be an event like iron banner yet more exclusive. Rumor is 1 coin will get you a ticket. The more you win the better the loot becomes, but lose 3 times and youre out.
Im assuming entry will be near the speaker, by that big door
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Its not an event, its a dlc playlist. The exotic bounty for the Fate of all Fools involves them.