Verizon is the last of the big four carriers to serve Android Pie to the Galaxy Note 910
Samsung's latest S Pen-wielding flagship started receiving the newest version of Android with One UI on top a couple of months ago outside the US, while AT&T got the ball rolling among the nation's major mobile network operators just a couple of weeks after that. Even though Sprint followed suit surprisingly quickly, it took almost another month for T-Mobile to join the party.
At long last, Verizon has revised its Galaxy Note 9 support webpage earlier today to include the detailed changelog of the handset's Android 9 Pie promotion, scheduled for an over-the-air release on March 12. That's also today, but judging from the silence on the matter on the phone's dedicated subreddit, we're guessing the actual OTA delivery still needs a few more hours before kicking off.
Once that happens, you may have to wait even longer for Verizon to spread the love nationwide, although we're probably talking a few days tops. In the meantime, try not to abuse the "Check for Updates" option under "Settings", "About phone", and finally, "Software updates." We know it's not easy to be patient, considering Google first released Android Pie all the way back in August 2018.
Apart from the search giant's standard goodies and enhancements, including Adaptive Battery and Adaptive Brightness functionality, the Galaxy Note 9 is also getting a bunch of Samsung-specific One UI tweaks and add-ons. Most notably, a system-wide Night mode feature and vastly improved one-handed operation.