If my memory serves me correctly, Samsung had similar misinformation regarding an update for the Galaxy S7, that never was going to happen & never did.
Shades of Samsung's support chat, insisting that Canada was "definitely" getting the beta of x Android version.
According to Telus OS update schedule, the S9 has only received 2 security patch updates this year, one in January & the second security patch update was scheduled for February 17th.
There's no mention of any Android version update yet.
If it's shown as completed, not in North America, maybe Europe?