Correct me if I get this wrong but with the old GW I thought you could set your defenses for the week any time prior to the day in question? So if you forget to do so Monday, that’s only one day out of six that you missed.
But with the new GW, if you forget to set a defense team then that’s it for the entire GW. This prep time really needs to be expanded.
even better, towards the end of the old GW, the defenses “tried” to remember the last defense set so even if you are gone for the first half of the week, you might still have something set. Might not actually have been the right defense sometimes, but it was better than nothing.