If you’ve logged into the 11.2 PTR, you may have spotted it: 
Delver’s Bounty, that provides players with Hero-track loot, is locked until you hit Delver’s Journey Level 2. And that means no freebie Hero gear on Season launch week for most players.
No Level 2, No Bounty
As you can see in the screenshot provided by Redditor Popicus, you may acquire Delver’s Bounties from Bountiful Delves once per week starting with Level 2.
Delver’s Bounty Season 3 Change
byu/Popicus inwow
How Long is the Delay?
Level 2 shouldn’t be a big grind and you should hit it during Week 2 of Season 3 without any issues, unless Blizzard has changed the XP requirements on the Delver’s Journey track.