Does the availability as shown on KVS or other tools update First availability as status upgrades clear, for example on DL or US?
e.g. For the next LGA->ATL flight as of this writing, at 3pm, it shows F1 A0 availability; the following flight at 3:59pm has F4 A3 availability. Seat maps on Delta.com seem to roughly agree--3pm flight has 1 unassigned first seat, 3:59pm flight has five unassigned first seats (suggesting one person hasn't checked in yet).
But can there really be that many empty First seats on a LGA-ATL flight? I would think there would be enough status-holders on such a flight to fill up the seats in front, and well before the day of departure.