The update carries build number N960FXXU2CSA7 and weighs in at 129.42MB. The changelog isn’t particularly descriptive about what changes it brings, so they’re most likely bug fixes and optimizations. It is common for Samsung to release such updates without explicitly mentioning what they do. The next update will very likely be the February security patch as the Note 9’s Android Pie build came with the January security patch.
You can see if the update is available for your device by going into the Settings » Software update menu and tapping Download updates manually. Do let us know in the comments below if you’ve received the update and noticed any changes on your Galaxy Note 9.