I noticed on my LG Aristo for T-Mobile even without an active sim it prompted me for an update.

This update includes:

Android Security Patch Level update from April 1st, 2017 -> September 1st, 2017.

Also noticed the color scheme for the LG Video app was changed from blue to purple(ie: Some LG system apps might have got secretly updated as well.)

For me it was 446 Megabytes in size.