The court only struck down the temporary travel ban.
It was a 90 day travel ban that would have expired by now.
The author of the article seems confused.
Extreme vetting has been in place for a while and the travel ban is not needed. This is moving forward only as a PR stunt at this point.
Trump is intentionally moving it forward because of the principle involved. He could drop it, because, as you say, they are using extreme vetting anyway.