If you have only earned 12,000 status points this year, then you won't receive any new SNUs. If you qualified for Platinum this year, by earning >14,000 points last year, your SNUs would have been awarded as soon as you crossed over 14,000 points in your account. You don't then get additional SNUs the following year, unless you again cross the relevant point thresholds. SNUs aren't awarded on Jan 1 of the new year, based on your points earned in the previous year. The SNUs are awarded immediately, as the points post.

As soon as you earn 14,000 this year, you will get 2 more SNUs, expiring 31/12/2023, and at the same time, extend your Platinum status into 2023.. You'll get the third as you cross 18,000. You'll get the fourth as you cross 22,000... Right up to a maximum of 12 total SNUs.