[Update: Sprint is also rolling out the update, but there is only December 2018 security patch. The size of the update is 196.05 MB. The software version is N960USQU1ARL1]
This update brings Camera preview improvement along December 2018 security patch, providing fixes to 40 Samsung Vulnerabilities and Exposures (SVE) items.
It also includes New Calling Service Enhancement – Caller Verified (Stir/Shaken) simply known as a caller ID and scam protection feature from the carrier.
The Galaxy Note 9 is receiving this update as the build version N960USQU1ARL1. If you want to check this update manually, head into Settings > System updates > Check for system updates or you can simply wait till the update automatically appears on your phone.