Was hoping I was on to something when I found the wifi calling turned off. My home location where I make most of my calls has somewhat crappy Verizon signal and so I was naturally quite happy to have a wifi calling option on my past recent devices. So finding it off after the 8.1 update kind of made sense for greater battery usage. But, not the case as battery is still losing 8%(last nite)over nite. In another thread it was mentioned that the update might have recalibrated the battery meter to a more realistic rate of decline. One thing I've been noticing is that while it seems to drop faster initially it tends to slow down a bit later in the day. Or just my imagination. I prefer the old battery meter.
EDIT: Some curious things I noticed after the update as far as changes, As mentioned my wifi calling was turned off and my preferred network had changed back to default of Global. Put these both back to where i had them set, but another weird thing that changed is I lost developer options. I had to go back in and do the tap dance to get it to reappear. Anyone else have any of this weirdness happen to their pixel? Or maybe it's all "normal" after an update, even a fairly minor one? I don't recall any of this with my old HTC 10, Moto's or Samsungs, but this is my first Pixel. I have the smaller P2.