This was what they said about it: [quote]Removing Exclusive Fullscreen We want to share some news today about an update coming to the PC version of Destiny 2 when Codename: Frontiers launches later this year. As you can guess by the title of this section, we plan to remove the exclusive fullscreen option in favor of windowed fullscreen, which will be renamed to fullscreen then. The windowed and borderless windowed options will stay as they are now. The reason for this change is simple. Our technology partners recommend this update as it offers performance that is as good, if not better, than the traditional exclusive fullscreen option. It also allows for faster Alt-Tab switching, which we know is very important for many Destiny players that use third party tools and websites; and a better integration with modern display features. This way we can simplify development and focus on fixes and improvements that matter most. This new fullscreen mode will handle resolution changes identically to how the current one does, and once the update is live, players that were using either exclusive fullscreen or windowed fullscreen will switch to the new setting automatically.[/quote] I wouldn't count on them bringing it back again since it let them drop it from testing etc.