It says on Hearthstone news:
June 17, 9:00 a.m. PT: Complete Chapter 1 in the Trial by Felfire adventure and earn 1 Ashes of Outland pack, 1 Year of the Dragon pack, and 1 Rise of Shadows pack.
It’s 11. a.m. PT now, but I haven’t received a legendary quest and also no pack rewards after completing the first chapter.
Am I missing something?
Quest line came like an hour after adventure was released. Now I have the quest to complete chapter 1 and I am already at chapter 2. I hope it doesn’t void the questline
Just got the quest. I wonder if it will work if I’ve already completed chapter 1.
Didn’t work for me 
It doesn’t. Beating any future chapter doesn’t unlock it. Beating the 4th lvl again doesn’t unlock it either. Seems bugged
It seems that my chapter 1 quest is now bugged because I’ve completed the chapter before I got the quest. I tried completing chapter 1 for the second time, but it didn’t work
Ahh. im having the same issue, quest showed up ages after the adventure and i had already completed chapter 1. Came here to see if anyone else had similar. Im using a samsung galaxy s7 if that makes any difference.
its a bug, its posted in the bug forum aswell…we just have to wait on this crap company to fix their sh1t…
well, guess ill do it on my european server than while im waiting. cheers.
Small indie company memes
Same thing, except i got to third chapter and nothing changed. Did i messed up? Is It fixable?
I’m sure Blizzard will fix it/compensate because a lot of people are having this issue.
Just for te records, here’s the post from Blue concerning the bug and the promised fix:
Thank you to everyone who reported issues with completing the Legendary Quest for the new adventure. For players who completed the adventure shortly after it was released, it’s possible that you didn’t yet have the Legendary Quest and won’t be able to complete it with repeated playthroughs. We’re working on a fix that will check for adventure completion and whether you’ve gotten your rewards and grant quest completion to anyone who didn’t receive it. You will not need to complete the adventure again as long as you have completed it once. We’re likely going to get this fix out early next week.
Source: https://www.reddit.com/r/hearthstone/comments/hawvo3/legendary_quest_bugged_out/fv9ax01/
Funny thing is, I saw the bug mentioned online, launched HS and saw the Quest. Feeling save I played thru the first chapter of the adventure, but the quest didn’t count it as completed. Restarting the game and/or replaying chapter 1 didn’t work, either.
Now I’m just hoping the solution mentioned in the quote above does work for me, too. 
Worked liked promised after the hotfix (replaying last part of chapter 1). Even got the legendary spell Evocation in the AoO pack.
Well - time to dust (figuratively speaking) my Mage collection, I guess.
Wasnt’t it said in the Battle.net client that they will perform maintenance only on 25th? Anyway I’ll try it later today.
Nice to know. Thanks!