Samsung will usually release the update for unlocked models first while they are working with the various carriers to get the carrier specific code from the carriers so Samsung can incorporate it into the base code. Then the carriers have test the updated code to verify it doesn't effect the phones or the network. If it passes all the tests, Samsung uploads the update to the servers and coordinates with the carrier on when the update is released.
When the update is released, it will be posted on the link below.
https://www.verizonwireless.com/support/samsung-galaxy-note9-update/
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