Destiny: Nightfall & Heroic strikes to take place on different levels following HoW's release
Going forward, Destiny's weekly Heroic and Nightfall strikes will be separate.
Bungie has revealed that following the launch of House of Wolves, the weekly Heroic and Nightfall strikes will be decoupled. That means that for the first time in Destiny, these weekly events will not take place on the same level.
The move is done to ensure that those who don't have access to the House of Wolves DLC can still play at least one weekly activity and not be locked out of both like they were when The Dark Below launched.
Bungie added that in the couple of weeks following the launch of House of Wolves, the rotation will heavily feature House of Wolves strikes.
Thanks, IGN.