Based on your battery saver question, I investigated further. Yes, battery saver is on, and prior to the update the glance screen worked correctly with battery saver on. Apparently now the glance screen does not show with battery saver on as it did before. I noticed that the only glance screen setting that shows with battery saver on is the on/off setting (which I mentioned reverts back to off) and no additional settings (Show Glance screen for, etc.) show when battery saver is turned on. With battery saver off, turning glance screen on reveals all of the expected additional settings and glance screen works.
This is a change from pre-Creators Update. It may have happened because I touched the battery saver and glance screen settings after the update. I have a second phone that has also updated and I have not touched any settings for glance screen or battery saver. When it's available I will check it to see if the glance screen is still working after the Creator Update.
Regarding my AT&T question, I wanted to indicate what my service provider was since (I believe) update pushes are controlled by the provider. You're correct that AT&T does not sell the 950XL, and in fact their system doesn't seem to be able to recognize it as such. My account shows both of our 950XLs and unknown devices, and I've worked many hours with AT&T to correct this. I gave up because they could never figure it out. But I digress...