Just got the one UI 2.0 update on my Sprint note 9! Use smart switch app on computer to find it. If it doesn't show up reinstall USB drivers and try again. It should show up afterwards. It's a big update, so it may take a while to download it (make sure your computer has a good internet connection). Update is running great on my phone too!
I read somewhere it was supposed to roll out February 24th. I have yet to receive the update. I am a Note 9 locked user. Unlocked Note 9's have received the update. The S series have started to receive the update as well.
As of right now, there are no indications of when the update will roll out.
Some of us force push the update through...meaning that if you go to settings and select update manually you can sometimes force the download to begin before Sprint pushes it to your phone automatically.
In part I believe that is why some have received the updates and others have not. In addition a lot of different things effect the push hitting your phone so they don't all hit at the exact same time but if you want to go into your phone and go to settings>system updates>download and install, you can see if you can force the push to your device.