During Upfronts, networks often orphan primetime programs and series by not renewing them. Not wanting to tip their hands about who would survive and who would not, often these shows are "phantom" scheduled for summer reruns just so salespeople have something to sell other than TBA.
Once cancelled, the shows often vanish from air. In Brooklyn 99's case, Fox had scheduled re-runs on Sundays all through this summer. Once NBC decided to (
As each network makes new season announcements, the summer schedule will be modified. So if you are working on a formal proposal for this summer, understand it will not remain valid for long.
My clients should be updated by next week. Because of the massive methodology change coming to Nielsen's data, the fall of 2018 will be a nightmare for stations who care. For Sinclair, it's a jackpot.