I never got it either. There's a big difference between a live action adaptation of something that is thoroughly fantastical such as Jungle Book/Beauty and the Beast/Lion King and... Mary Popins... a very small scale, subdued, and frankly antiquated property that was only really relevant to the parents of the parents of the kids who saw Lion King or Alladin in theaters.
If there was to be a Poppins sequel/remake, playing it straight comes decades too late, and doing it now without some sort of an actual twist on its approach (going hard Classic Disney) It's an experience that is going to seem inconsequential to a large swath of audience goers.
That said, I don't think that day 2 drops for movies that released mid week are that unheard of. The movie might be a little soft, but it had some pretty good PS going in so I don't think that it will be a bomb, just soft as it won't have much broad appeal past 'old people and wholesome families with young kids wanting to see a pg old times Disney flick over the holidays'. It's goimg to appeal to the same types of people who were wanting to see Saving Mr Banks.
I sound like I'm being super down on it, but that's just relative to the 'it will crush everything' narrative. It will have its audience and do decently for itself imo. It looks very well made.