When the next Destiny expansion leaked two weeks ago we thought that the official reveal would take place during Sony's E3 press conference. We were wrong.
During Bungie's Weekly Update David Dague announced that they'll talk about the next expansion on June 9th:
"This week at Bungie we're preparing to reveal your next adventure.
You're invited to learn all about the next threat that you'll confront as Guardians.
Destiny Reveal Stream
Thursday, June 9th, 10 AM Pacific
TWITCH.TV/BUNGIE"
This means that the official reveal will take place at 6 pm BST / 7pm CEST.