There is no knitting this year. Knitting was only supposed to be available in Winter Bash 2018; it was repeated as a special circumstance in Winter Bash 2019.
Winter Bash usually takes on a different theme1 every year, except for last year's (2019) which was a "recycled" Winter Bash.
It is the same theme as 2018 (and yes, you can knit once more). Sorry, not enough bandwidth here to make a brand new theme this time around. And the knitting is pretty cool. (Mostly) different hats and missions. And even though it is starting on the 9th, it will run through the end of Jan 1 (as usual)
from Yaakov Ellis
That also explains why knitting was available for two consecutive Winter Bashes (due to the recycled Winter Bash theme).
1The theme I'm referring to is the site design which sometimes comes with a game / activity as part of the theme, e.g. knitting in 2018/19 and the Hat Dash game in 2020.