It sounds like Microsoft will announce a Quantum Break release date at its gamescom conference tomorrow.
Speaking in reply to a user to asked if we'll get a date for the game soon, Spencer replied hinting that we would.
@VagelisVala You'll see on Tuesday. I think you'll be happy.— Phil Spencer (@XboxP3) August 1, 2015
Quantum Break has been in development for quite some time, so it'll be good to see more of it, along with Crackdown and Scalebound.
Sony won't hold a conference tomorrow since its so close to E3, so has instead opted to hold its conference at Paris Games Week, which takes place in October.