Ideally, like all tech migrations. But the schedules were already changed in November so pre 6am departures have been cancelled

I assume the post you’re replying to says it’s surprising they’d cancel the east coast early departure bank. However, this likely enables the maximum west coast - Asia and red eye departures, plus a consideration of the global knock on effects.

I assume, given this has been actioned since at least November, that there is sufficient evidence internally that the first Wednesday morning in February is the quietest/least consequential travel day across the network