One of the mysteries of Dragonflight it seems is being given a single copper coin, which leads to another quest where you get a curious coin. The quest text on the coin gives away who it’s from.
"A single, strange coin sits in your bag, along with a small note: “Thank you for the opportunity to observe you. The information I’ve gathered has been illuminating, to say the least. This will be my final gift… for now.”
I do believe this coin was slipped into our pocket by Shadreen The Watcher- An Ethereal who was behind the mystery of the Brawler’s Guild. “Thank you for the opportunity to observe you.” this is a throwback to the Shadowscralled tome that you get from killing her minion Xan-Sallish, which reads
“You are my eyes when my eyes are elsewhere. See everything. Remember, record, report. The way they move, the way they fight, their choice of armor, their taste in weapons. Let no detail elude you. Pay special attention to the heroes, the champions, the movers of fate. Watch from afar. Watch when up close. Interfere, if you deem it necessary. Do not fail me, Xan-Sallish. Know that I have eyes on you, too."
In the Alliance quest Solving the Mystery, there’s a similar one for Horde, but here’s the link. https://wowpedia.fandom.com/wiki/Solving_the_Mystery_(Alliance)
Bizmo says “We’ve had our suspicions about this “Watcher” character since the incident in Quel’Danas. It seems the rumors are true. They are watching us.”
The Incident in Quel’Danas may refer to the Nightborne recruitment scenario, where the Void tried to corrupt the Sunwell using Alleria Windrunner. Or may refer to the Battle of Quel’danas, The Sunwell Raid.
If this incident that Shadreen was behind was the Battle of Quel’Danas then there’s a connection between her and Sathrovarr the Corruptor, A Dreadlord and part of the first boss encounter of the Sunwell Plateau raid. He possessed Kalecgos.
Moving forward in Dragonflight this may lead to some potential story where Kalecgos gets to confront and defeat Sathrovarr the Corruptor for good. Or this could also be forshadowing some Old God machinations, as the Brawler’s Guild revealed that minions of the Old Gods were at play there as well. This seems like it may be forshadowing Act 2 or Act 3 plot involving the Ethereals and the Void.