The One UI 2.0 update should be available from next week, Monday. According to a Reddit post, the update will be available via the Smart Switch app on PC beginning this Sunday, with the wider OTA rollout to follow hours later.
T-Mobile also gives a hint, T-Mobile says, On January 26, 2020, an Android software update will be released for Samsung Note, Galaxy S9, and Galaxy S9+ phones. To be specific, there is no mention of Android 10 and One UI 2.0 software update.
Additionally, a Verizon support representative said, the Galaxy Note 9 Android 10 update should be released before February 2020.
Meanwhile, you can also check for the software update by heading into the device Settings then Software update menu and go for the Download and install option.